From a5960f52f439db965c33f24e8915bc8782daab2a Mon Sep 17 00:00:00 2001
From: bcumming <bcumming@cscs.ch>
Date: Mon, 3 Oct 2016 16:04:24 +0200
Subject: [PATCH] move json git submodule into main respository
---
.gitmodules | 3 -
external/json | 1 -
json/.gitignore | 7 +
json/.travis.yml | 44 +
json/LICENSE.MIT | 22 +
json/README.md | 398 +++
json/json.hpp | 7290 ++++++++++++++++++++++++++++++++++++++++++++++
7 files changed, 7761 insertions(+), 4 deletions(-)
delete mode 160000 external/json
create mode 100644 json/.gitignore
create mode 100644 json/.travis.yml
create mode 100644 json/LICENSE.MIT
create mode 100644 json/README.md
create mode 100644 json/json.hpp
diff --git a/.gitmodules b/.gitmodules
index ae780729..37c5b86e 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,9 +1,6 @@
[submodule "vector"]
path = external/vector
url = git@github.com:bcumming/vector.git
-[submodule "json"]
- path = external/json
- url = git@github.com:bcumming/json.git
[submodule "modparser"]
path = external/modparser
url = git@github.com:eth-cscs/modparser.git
diff --git a/external/json b/external/json
deleted file mode 160000
index 2225c365..00000000
--- a/external/json
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 2225c36583acfa51e4f26529c1195d50e3604ac9
diff --git a/json/.gitignore b/json/.gitignore
new file mode 100644
index 00000000..4210a192
--- /dev/null
+++ b/json/.gitignore
@@ -0,0 +1,7 @@
+json_unit
+json_benchmarks
+
+working
+
+html
+me.nlohmann.json.docset
diff --git a/json/.travis.yml b/json/.travis.yml
new file mode 100644
index 00000000..62330af8
--- /dev/null
+++ b/json/.travis.yml
@@ -0,0 +1,44 @@
+language: cpp
+
+sudo: false
+
+# from http://stackoverflow.com/a/32127147/266378
+matrix:
+ include:
+ - os: linux
+ compiler: gcc
+ addons:
+ apt:
+ sources: ['ubuntu-toolchain-r-test']
+ packages: ['g++-4.9', 'valgrind', 'python-pip', 'python-yaml']
+ before_script:
+ - pip install --user git+git://github.com/eddyxu/cpp-coveralls.git
+ env: COMPILER=g++-4.9
+
+ - os: linux
+ compiler: gcc
+ addons:
+ apt:
+ sources: ['ubuntu-toolchain-r-test']
+ packages: ['g++-5', 'valgrind']
+ env: COMPILER=g++-5
+
+ - os: linux
+ compiler: clang
+ addons:
+ apt:
+ sources: ['ubuntu-toolchain-r-test', 'llvm-toolchain-precise-3.6']
+ packages: ['clang-3.6', 'valgrind']
+ env: COMPILER=clang++-3.6
+
+script:
+ - make CXX=$COMPILER CXXFLAGS="-lstdc++"
+ - ./json_unit "*"
+ - valgrind --error-exitcode=1 --leak-check=full ./json_unit
+
+after_success:
+ - if [ "$COMPILER" = "g++-4.9" ]; then make clean ; fi
+ - if [ "$COMPILER" = "g++-4.9" ]; then touch src/json.hpp ; fi
+ - if [ "$COMPILER" = "g++-4.9" ]; then make json_unit CXXFLAGS="-fprofile-arcs -ftest-coverage -std=c++11 -lstdc++" CXX=$COMPILER ; fi
+ - if [ "$COMPILER" = "g++-4.9" ]; then ./json_unit "*" ; fi
+ - if [ "$COMPILER" = "g++-4.9" ]; then coveralls --exclude test/catch.hpp --exclude test/unit.cpp --include src/json.hpp --gcov-options '\-lp' --gcov 'gcov-4.9' ; fi
diff --git a/json/LICENSE.MIT b/json/LICENSE.MIT
new file mode 100644
index 00000000..18332db3
--- /dev/null
+++ b/json/LICENSE.MIT
@@ -0,0 +1,22 @@
+The library is licensed under the MIT License
+<http://opensource.org/licenses/MIT>:
+
+Copyright (c) 2013-2015 Niels Lohmann
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/json/README.md b/json/README.md
new file mode 100644
index 00000000..76c32d44
--- /dev/null
+++ b/json/README.md
@@ -0,0 +1,398 @@
+
+
+[](https://travis-ci.org/nlohmann/json)
+[](https://ci.appveyor.com/project/nlohmann/json)
+[](https://coveralls.io/r/nlohmann/json)
+[](http://melpon.org/wandbox/permlink/GnGKwji06WeVonlI)
+[](http://nlohmann.github.io/json)
+[](https://raw.githubusercontent.com/nlohmann/json/master/LICENSE.MIT)
+[](https://github.com/nlohmann/json/releases)
+[](http://github.com/nlohmann/json/issues)
+
+## Design goals
+
+There are myriads of [JSON](http://json.org) libraries out there, and each may even have its reason to exist. Our class had these design goals:
+
+- **Intuitive syntax**. In languages such as Python, JSON feels like a first class data type. We used all the operator magic of modern C++ to achieve the same feeling in your code. Check out the [examples below](#examples) and you know, what I mean.
+
+- **Trivial integration**. Our whole code consists of a single header file `json.hpp`. That's it. No library, no subproject, no dependencies, no complex build system. The class is written in vanilla C++11. All in all, everything should require no adjustment of your compiler flags or project settings.
+
+- **Serious testing**. Our class is heavily [unit-tested](https://github.com/nlohmann/json/blob/master/test/json_unit.cc) and covers [100%](https://coveralls.io/r/nlohmann/json) of the code, including all exceptional behavior. Furthermore, we checked with [Valgrind](http://valgrind.org) that there are no memory leaks.
+
+Other aspects were not so important to us:
+
+- **Memory efficiency**. Each JSON object has an overhead of one pointer (the maximal size of a union) and one enumeration element (1 byte). The default generalization uses the following C++ data types: `std::string` for strings, `int64_t` or `double` for numbers, `std::map` for objects, `std::vector` for arrays, and `bool` for Booleans. However, you can template the generalized class `basic_json` to your needs.
+
+- **Speed**. We currently implement the parser as naive [recursive descent parser](http://en.wikipedia.org/wiki/Recursive_descent_parser) with hand coded string handling. It is fast enough, but a [LALR-parser](http://en.wikipedia.org/wiki/LALR_parser) with a decent regular expression processor should be even faster (but would consist of more files which makes the integration harder).
+
+## Integration
+
+The single required source, file `json.hpp` is in the `src` directory or [released here](https://github.com/nlohmann/json/releases). All you need to do is add
+
+```cpp
+#include "json.hpp"
+
+// for convenience
+using json = nlohmann::json;
+```
+
+to the files you want to use JSON objects. That's it. Do not forget to set the necessary switches to enable C++11 (e.g., `-std=c++11` for GCC and Clang).
+
+## Supported compilers
+
+Though it's 2015 already, the support for C++11 is still a bit sparse. Currently, the following compilers are known to work:
+
+- GCC 4.8 - 5.2
+- Clang 3.4 - 3.7
+- Microsoft Visual C++ 14.0 RC
+
+I would be happy to learn about other compilers/versions.
+
+## Examples
+
+Here are some examples to give you an idea how to use the class.
+
+Assume you want to create the JSON object
+
+```json
+{
+ "pi": 3.141,
+ "happy": true,
+ "name": "Niels",
+ "nothing": null,
+ "answer": {
+ "everything": 42
+ },
+ "list": [1, 0, 2],
+ "object": {
+ "currency": "USD",
+ "value": 42.99
+ }
+}
+```
+
+With the JSON class, you could write:
+
+```cpp
+// create an empty structure (null)
+json j;
+
+// add a number that is stored as double (note the implicit conversion of j to an object)
+j["pi"] = 3.141;
+
+// add a Boolean that is stored as bool
+j["happy"] = true;
+
+// add a string that is stored as std::string
+j["name"] = "Niels";
+
+// add another null object by passing nullptr
+j["nothing"] = nullptr;
+
+// add an object inside the object
+j["answer"]["everything"] = 42;
+
+// add an array that is stored as std::vector (using an initializer list)
+j["list"] = { 1, 0, 2 };
+
+// add another object (using an initializer list of pairs)
+j["object"] = { {"currency", "USD"}, {"value", 42.99} };
+
+// instead, you could also write (which looks very similar to the JSON above)
+json j2 = {
+ {"pi", 3.141},
+ {"happy", true},
+ {"name", "Niels"},
+ {"nothing", nullptr},
+ {"answer", {
+ {"everything", 42}
+ }},
+ {"list", {1, 0, 2}},
+ {"object", {
+ {"currency", "USD"},
+ {"value", 42.99}
+ }}
+};
+```
+
+Note that in all these cases, you never need to "tell" the compiler which JSON value you want to use. If you want to be explicit or express some edge cases, the functions `json::array` and `json::object` will help:
+
+```cpp
+// a way to express the empty array []
+json empty_array_explicit = json::array();
+
+// ways to express the empty object {}
+json empty_object_implicit = json({});
+json empty_object_explicit = json::object();
+
+// a way to express an _array_ of key/value pairs [["currency", "USD"], ["value", 42.99]]
+json array_not_object = { json::array({"currency", "USD"}), json::array({"value", 42.99}) };
+```
+
+### Serialization / Deserialization
+
+You can create an object (deserialization) by appending `_json` to a string literal:
+
+```cpp
+// create object from string literal
+json j = "{ \"happy\": true, \"pi\": 3.141 }"_json;
+
+// or even nicer (thanks http://isocpp.org/blog/2015/01/json-for-modern-cpp)
+auto j2 = R"(
+ {
+ "happy": true,
+ "pi": 3.141
+ }
+)"_json;
+
+// or explicitly
+auto j3 = json::parse("{ \"happy\": true, \"pi\": 3.141 }");
+```
+
+You can also get a string representation (serialize):
+
+```cpp
+// explicit conversion to string
+std::string s = j.dump(); // {\"happy\":true,\"pi\":3.141}
+
+// serialization with pretty printing
+// pass in the amount of spaces to indent
+std::cout << j.dump(4) << std::endl;
+// {
+// "happy": true,
+// "pi": 3.141
+// }
+```
+
+You can also use streams to serialize and deserialize:
+
+```cpp
+// deserialize from standard input
+json j;
+std::cin >> j;
+
+// serialize to standard output
+std::cout << j;
+
+// the setw manipulator was overloaded to set the indentation for pretty printing
+std::cout << std::setw(4) << j << std::endl;
+```
+
+These operators work for any subclasses of `std::istream` or `std::ostream`.
+
+### STL-like access
+
+We designed the JSON class to behave just like an STL container. In fact, it satisfies the [**ReversibleContainer**](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) requirement.
+
+```cpp
+// create an array using push_back
+json j;
+j.push_back("foo");
+j.push_back(1);
+j.push_back(true);
+
+// iterate the array
+for (json::iterator it = j.begin(); it != j.end(); ++it) {
+ std::cout << *it << '\n';
+}
+
+// range-based for
+for (auto element : j) {
+ std::cout << element << '\n';
+}
+
+// getter/setter
+const std::string tmp = j[0];
+j[1] = 42;
+bool foo = j.at(2);
+
+// other stuff
+j.size(); // 3 entries
+j.empty(); // false
+j.type(); // json::value_t::array
+j.clear(); // the array is empty again
+
+// convenience type checkers
+j.is_null();
+j.is_boolean();
+j.is_number();
+j.is_object();
+j.is_array();
+j.is_string();
+
+// comparison
+j == "[\"foo\", 1, true]"_json; // true
+
+// create an object
+json o;
+o["foo"] = 23;
+o["bar"] = false;
+o["baz"] = 3.141;
+
+// special iterator member functions for objects
+for (json::iterator it = o.begin(); it != o.end(); ++it) {
+ std::cout << it.key() << " : " << it.value() << "\n";
+}
+
+// find an entry
+if (o.find("foo") != o.end()) {
+ // there is an entry with key "foo"
+}
+
+// or simpler using count()
+int foo_present = o.count("foo"); // 1
+int fob_present = o.count("fob"); // 0
+
+// delete an entry
+o.erase("foo");
+```
+
+### Conversion from STL containers
+
+Any sequence container (`std::array`, `std::vector`, `std::deque`, `std::forward_list`, `std::list`) whose values can be used to construct JSON types (e.g., integers, floating point numbers, Booleans, string types, or again STL containers described in this section) can be used to create a JSON array. The same holds for similar associative containers (`std::set`, `std::multiset`, `std::unordered_set`, `std::unordered_multiset`), but in these cases the order of the elements of the array depends how the elements are ordered in the respective STL container.
+
+```cpp
+std::vector<int> c_vector {1, 2, 3, 4};
+json j_vec(c_vector);
+// [1, 2, 3, 4]
+
+std::deque<double> c_deque {1.2, 2.3, 3.4, 5.6};
+json j_deque(c_deque);
+// [1.2, 2.3, 3.4, 5.6]
+
+std::list<bool> c_list {true, true, false, true};
+json j_list(c_list);
+// [true, true, false, true]
+
+std::forward_list<int64_t> c_flist {12345678909876, 23456789098765, 34567890987654, 45678909876543};
+json j_flist(c_flist);
+// [12345678909876, 23456789098765, 34567890987654, 45678909876543]
+
+std::array<unsigned long, 4> c_array {{1, 2, 3, 4}};
+json j_array(c_array);
+// [1, 2, 3, 4]
+
+std::set<std::string> c_set {"one", "two", "three", "four", "one"};
+json j_set(c_set); // only one entry for "one" is used
+// ["four", "one", "three", "two"]
+
+std::unordered_set<std::string> c_uset {"one", "two", "three", "four", "one"};
+json j_uset(c_uset); // only one entry for "one" is used
+// maybe ["two", "three", "four", "one"]
+
+std::multiset<std::string> c_mset {"one", "two", "one", "four"};
+json j_mset(c_mset); // only one entry for "one" is used
+// maybe ["one", "two", "four"]
+
+std::unordered_multiset<std::string> c_umset {"one", "two", "one", "four"};
+json j_umset(c_umset); // both entries for "one" are used
+// maybe ["one", "two", "one", "four"]
+```
+
+Likewise, any associative key-value containers (`std::map`, `std::multimap`, `std::unordered_map`, `std::unordered_multimap`) whose keys are can construct an `std::string` and whose values can be used to construct JSON types (see examples above) can be used to to create a JSON object. Note that in case of multimaps only one key is used in the JSON object and the value depends on the internal order of the STL container.
+
+```cpp
+std::map<std::string, int> c_map { {"one", 1}, {"two", 2}, {"three", 3} };
+json j_map(c_map);
+// {"one": 1, "two": 2, "three": 3}
+
+std::unordered_map<const char*, double> c_umap { {"one", 1.2}, {"two", 2.3}, {"three", 3.4} };
+json j_umap(c_umap);
+// {"one": 1.2, "two": 2.3, "three": 3.4}
+
+std::multimap<std::string, bool> c_mmap { {"one", true}, {"two", true}, {"three", false}, {"three", true} };
+json j_mmap(c_mmap); // only one entry for key "three" is used
+// maybe {"one": true, "two": true, "three": true}
+
+std::unordered_multimap<std::string, bool> c_ummap { {"one", true}, {"two", true}, {"three", false}, {"three", true} };
+json j_ummap(c_ummap); // only one entry for key "three" is used
+// maybe {"one": true, "two": true, "three": true}
+```
+
+### Implicit conversions
+
+The type of the JSON object is determined automatically by the expression to store. Likewise, the stored value is implicitly converted.
+
+```cpp
+/// strings
+std::string s1 = "Hello, world!";
+json js = s1;
+std::string s2 = js;
+
+// Booleans
+bool b1 = true;
+json jb = b1;
+bool b2 = jb;
+
+// numbers
+int i = 42;
+json jn = i;
+double f = jn;
+
+// etc.
+```
+
+You can also explicitly ask for the value:
+
+```cpp
+std::string vs = js.get<std::string>();
+bool vb = jb.get<bool>();
+int vi = jn.get<int>();
+
+// etc.
+```
+
+## License
+
+<img align="right" src="http://opensource.org/trademarks/opensource/OSI-Approved-License-100x137.png">
+
+The class is licensed under the [MIT License](http://opensource.org/licenses/MIT):
+
+Copyright © 2013-2015 [Niels Lohmann](http://nlohmann.me)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+## Thanks
+
+I deeply appreciate the help of the following people.
+
+- [Teemperor](https://github.com/Teemperor) implemented CMake support and lcov integration, realized escape and Unicode handling in the string parser, and fixed the JSON serialization.
+- [elliotgoodrich](https://github.com/elliotgoodrich) fixed an issue with double deletion in the iterator classes.
+- [kirkshoop](https://github.com/kirkshoop) made the iterators of the class composable to other libraries.
+- [wancw](https://github.com/wanwc) fixed a bug that hindered the class to compile with Clang.
+- Tomas Ã…blad found a bug in the iterator implementation.
+- [Joshua C. Randall](https://github.com/jrandall) fixed a bug in the floating-point serialization.
+- [Aaron Burghardt](https://github.com/aburgh) implemented code to parse streams incrementally. Furthermore, he greatly improved the parser class by allowing the definition of a filter function to discard undesired elements while parsing.
+- [Daniel KopeÄek](https://github.com/dkopecek) fixed a bug in the compilation with GCC 5.0.
+- [Florian Weber](https://github.com/Florianjw) fixed a bug in and improved the performance of the comparison operators.
+- [Eric Cornelius](https://github.com/EricMCornelius) pointed out a bug in the handling with NaN and infinity values. He also improved the performance of the string escaping.
+- [易æ€é¾™](https://github.com/likebeta) implemented a conversion from anonymous enums.
+- [kepkin](https://github.com/kepkin) patiently pushed forward the support for Microsoft Visual studio.
+- [gregmarr](https://github.com/gregmarr) simplified the implementation of reverse iterators.
+- [Caio Luppi](https://github.com/caiovlp) fixed a bug in the Unicode handling.
+- [dariomt](https://github.com/dariomt) fixed some typos in the examples.
+- [Daniel Frey](https://github.com/d-frey) cleaned up some pointers and implemented exception-safe memory allocation.
+- [Colin Hirsch](https://github.com/ColinH) took care of a small namespace issue.
+- [Huu Nguyen](https://github.com/whoshuu) correct a variable name in the documentation.
+- [Silverweed](https://github.com/silverweed) overloaded `parse()` to accept an rvalue reference.
+- [dariomt](https://github.com/dariomt) fixed a subtlety in MSVC type support.
+
+Thanks a lot for helping out!
+
+## Execute unit tests
+
+To compile and run the tests, you need to execute
+
+```sh
+$ make
+$ ./json_unit "*"
+
+===============================================================================
+All tests passed (3341774 assertions in 27 test cases)
+```
+
+For more information, have a look at the file [.travis.yml](https://github.com/nlohmann/json/blob/master/.travis.yml).
diff --git a/json/json.hpp b/json/json.hpp
new file mode 100644
index 00000000..97b1089c
--- /dev/null
+++ b/json/json.hpp
@@ -0,0 +1,7290 @@
+/*!
+@mainpage
+
+These pages contain the API documentation of JSON for Modern C++, a C++11
+header-only JSON class.
+
+Class @ref nlohmann::basic_json is a good entry point for the documentation.
+
+@copyright The code is licensed under the [MIT
+ License](http://opensource.org/licenses/MIT):
+ <br>
+ Copyright © 2013-2015 Niels Lohmann.
+ <br>
+ Permission is hereby granted, free of charge, to any person
+ obtaining a copy of this software and associated documentation files
+ (the "Software"), to deal in the Software without restriction,
+ including without limitation the rights to use, copy, modify, merge,
+ publish, distribute, sublicense, and/or sell copies of the Software,
+ and to permit persons to whom the Software is furnished to do so,
+ subject to the following conditions:
+ <br>
+ The above copyright notice and this permission notice shall be
+ included in all copies or substantial portions of the Software.
+ <br>
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ SOFTWARE.
+
+@author [Niels Lohmann](http://nlohmann.me)
+@see https://github.com/nlohmann/json to download the source code
+*/
+
+#ifndef NLOHMANN_JSON_HPP
+#define NLOHMANN_JSON_HPP
+
+#include <algorithm>
+#include <array>
+#include <ciso646>
+#include <cmath>
+#include <cstdio>
+#include <functional>
+#include <initializer_list>
+#include <iomanip>
+#include <iostream>
+#include <iterator>
+#include <limits>
+#include <map>
+#include <memory>
+#include <sstream>
+#include <string>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+// enable ssize_t on MinGW
+#ifdef __GNUC__
+ #ifdef __MINGW32__
+ #include <sys/types.h>
+ #endif
+#endif
+
+// enable ssize_t for MSVC
+#ifdef _MSC_VER
+ #include <basetsd.h>
+ using ssize_t = SSIZE_T;
+#endif
+
+/*!
+@brief namespace for Niels Lohmann
+@see https://github.com/nlohmann
+*/
+namespace nlohmann
+{
+
+
+/*!
+@brief unnamed namespace with internal helper functions
+*/
+namespace
+{
+/// Helper for SFINAE tests that can "sink" any type
+template<typename T>
+using sink_type = void;
+
+/// Helper to determine whether there's a key_type for T.
+template<typename T, typename V=void>
+struct has_mapped_type
+ : std::false_type
+{};
+
+template<typename T>
+struct has_mapped_type<T, sink_type<typename T::mapped_type>>
+ : std::true_type
+{};
+
+/// "equality" comparison for floating point numbers
+template<typename T>
+static bool approx(const T a, const T b)
+{
+ return not (a > b or a < b);
+}
+}
+
+/*!
+@brief a class to store JSON values
+
+@tparam ObjectType type for JSON objects (@c std::map by default; will be used
+in @ref object_t)
+@tparam ArrayType type for JSON arrays (@c std::vector by default; will be used
+in @ref array_t)
+@tparam StringType type for JSON strings and object keys (@c std::string by
+default; will be used in @ref string_t)
+@tparam BooleanType type for JSON booleans (@c `bool` by default; will be used
+in @ref boolean_t)
+@tparam NumberIntegerType type for JSON integer numbers (@c `int64_t` by
+default; will be used in @ref number_integer_t)
+@tparam NumberFloatType type for JSON floating-point numbers (@c `double` by
+default; will be used in @ref number_float_t)
+@tparam AllocatorType type of the allocator to use (@c `std::allocator` by
+default)
+
+@requirement The class satisfies the following concept requirements:
+- Basic
+ - [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible):
+ JSON values can be default constructed. The result will be a JSON null value.
+ - [MoveConstructible](http://en.cppreference.com/w/cpp/concept/MoveConstructible):
+ A JSON value can be constructed from an rvalue argument.
+ - [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible):
+ A JSON value can be copy-constrcuted from an lvalue expression.
+ - [MoveAssignable](http://en.cppreference.com/w/cpp/concept/MoveAssignable):
+ A JSON value van be assigned from an rvalue argument.
+ - [CopyAssignable](http://en.cppreference.com/w/cpp/concept/CopyAssignable):
+ A JSON value can be copy-assigned from an lvalue expression.
+ - [Destructible](http://en.cppreference.com/w/cpp/concept/Destructible):
+ JSON values can be destructed.
+- Layout
+ - [StandardLayoutType](http://en.cppreference.com/w/cpp/concept/StandardLayoutType):
+ JSON values have
+ [standard layout](http://en.cppreference.com/w/cpp/language/data_members#Standard_layout):
+ All non-static data members are private and standard layout types, the class
+ has no virtual functions or (virtual) base classes.
+- Library-wide
+ - [EqualityComparable](http://en.cppreference.com/w/cpp/concept/EqualityComparable):
+ JSON values can be compared with `==`, see @ref
+ operator==(const_reference,const_reference).
+ - [LessThanComparable](http://en.cppreference.com/w/cpp/concept/LessThanComparable):
+ JSON values can be compared with `<`, see @ref
+ operator<(const_reference,const_reference).
+ - [Swappable](http://en.cppreference.com/w/cpp/concept/Swappable):
+ Any JSON lvalue or rvalue of can be swapped with any lvalue or rvalue of
+ other compatible types, using unqualified function call @ref swap().
+ - [NullablePointer](http://en.cppreference.com/w/cpp/concept/NullablePointer):
+ JSON values can be compared against `std::nullptr_t` objects which are used
+ to model the `null` value.
+- Container
+ - [Container](http://en.cppreference.com/w/cpp/concept/Container):
+ JSON values can be used like STL containers and provide iterator access.
+ - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer);
+ JSON values can be used like STL containers and provide reverse iterator
+ access.
+
+@internal
+@note ObjectType trick from http://stackoverflow.com/a/9860911
+@endinternal
+
+@see RFC 7159 <http://rfc7159.net/rfc7159>
+*/
+template <
+ template<typename U, typename V, typename... Args> class ObjectType = std::map,
+ template<typename U, typename... Args> class ArrayType = std::vector,
+ class StringType = std::string,
+ class BooleanType = bool,
+ class NumberIntegerType = int64_t,
+ class NumberFloatType = double,
+ template<typename U> class AllocatorType = std::allocator
+ >
+class basic_json
+{
+ private:
+ /// workaround type for MSVC
+ using basic_json_t = basic_json<ObjectType,
+ ArrayType,
+ StringType,
+ BooleanType,
+ NumberIntegerType,
+ NumberFloatType,
+ AllocatorType>;
+
+ public:
+
+ /////////////////////
+ // container types //
+ /////////////////////
+
+ /// @name container types
+ /// @{
+
+ /// the type of elements in a basic_json container
+ using value_type = basic_json;
+
+ /// the type of an element reference
+ using reference = value_type&;
+
+ /// the type of an element const reference
+ using const_reference = const value_type&;
+
+ /// a type to represent differences between iterators
+ using difference_type = std::ptrdiff_t;
+
+ /// a type to represent container sizes
+ using size_type = std::size_t;
+
+ /// the allocator type
+ using allocator_type = AllocatorType<basic_json>;
+
+ /// the type of an element pointer
+ using pointer = typename std::allocator_traits<allocator_type>::pointer;
+ /// the type of an element const pointer
+ using const_pointer = typename std::allocator_traits<allocator_type>::const_pointer;
+
+ // forward declaration
+ template<typename Base> class json_reverse_iterator;
+
+ /// an iterator for a basic_json container
+ class iterator;
+ /// a const iterator for a basic_json container
+ class const_iterator;
+ /// a reverse iterator for a basic_json container
+ using reverse_iterator = json_reverse_iterator<typename basic_json::iterator>;
+ /// a const reverse iterator for a basic_json container
+ using const_reverse_iterator = json_reverse_iterator<typename basic_json::const_iterator>;
+
+ /// @}
+
+
+ /*!
+ @brief returns the allocator associated with the container
+ */
+ static allocator_type get_allocator()
+ {
+ return allocator_type();
+ }
+
+
+ ///////////////////////////
+ // JSON value data types //
+ ///////////////////////////
+
+ /// @name JSON value data types
+ /// @{
+
+ /*!
+ @brief a type for an object
+
+ [RFC 7159](http://rfc7159.net/rfc7159) describes JSON objects as follows:
+ > An object is an unordered collection of zero or more name/value pairs,
+ > where a name is a string and a value is a string, number, boolean, null,
+ > object, or array.
+
+ To store objects in C++, a type is defined by the template parameters @a
+ ObjectType which chooses the container (e.g., `std::map` or
+ `std::unordered_map`), @a StringType which chooses the type of the keys or
+ names, and @a AllocatorType which chooses the allocator to use.
+
+ #### Default type
+
+ With the default values for @a ObjectType (`std::map`), @a StringType
+ (`std::string`), and @a AllocatorType (`std::allocator`), the default value
+ for @a object_t is:
+
+ @code {.cpp}
+ std::map<
+ std::string, // key_type
+ basic_json, // value_type
+ std::less<std::string>, // key_compare
+ std::allocator<std::pair<const std::string, basic_json>> // allocator_type
+ >
+ @endcode
+
+ #### Behavior
+
+ The choice of @a object_t influences the behavior of the JSON class. With
+ the default type, objects have the following behavior:
+
+ - When all names are unique, objects will be interoperable in the sense
+ that all software implementations receiving that object will agree on the
+ name-value mappings.
+ - When the names within an object are not unique, later stored name/value
+ pairs overwrite previously stored name/value pairs, leaving the used
+ names unique. For instance, `{"key": 1}` and `{"key": 2, "key": 1}` will
+ be treated as equal and both stored as `{"key": 1}`.
+ - Internally, name/value pairs are stored in lexicographical order of the
+ names. Objects will also be serialized (see @ref dump) in this order. For
+ instance, `{"b": 1, "a": 2}` and `{"a": 2, "b": 1}` will be stored and
+ serialized as `{"a": 2, "b": 1}`.
+ - When comparing objects, the order of the name/value pairs is irrelevant.
+ This makes objects interoperable in the sense that they will not be
+ affected by these differences. For instance, `{"b": 1, "a": 2}` and
+ `{"a": 2, "b": 1}` will be treated as equal.
+
+ #### Limits
+
+ [RFC 7159](http://rfc7159.net/rfc7159) specifies:
+ > An implementation may set limits on the maximum depth of nesting.
+
+ In this class, the object's limit of nesting is not constraint explicitly.
+ However, a maximum depth of nesting may be introduced by the compiler or
+ runtime environment. A theoretical limit can be queried by calling the @ref
+ max_size function of a JSON object.
+
+ #### Storage
+
+ Objects are stored as pointers in a `basic_json` type. That is, for any
+ access to object values, a pointer of type `object_t*` must be dereferenced.
+
+ @sa array_t
+ */
+ using object_t = ObjectType<StringType,
+ basic_json,
+ std::less<StringType>,
+ AllocatorType<std::pair<const StringType,
+ basic_json>>>;
+
+ /*!
+ @brief a type for an array
+
+ [RFC 7159](http://rfc7159.net/rfc7159) describes JSON arrays as follows:
+ > An array is an ordered sequence of zero or more values.
+
+ To store objects in C++, a type is defined by the template parameters @a
+ ArrayType which chooses the container (e.g., `std::vector` or `std::list`)
+ and @a AllocatorType which chooses the allocator to use.
+
+ #### Default type
+
+ With the default values for @a ArrayType (`std::vector`) and @a
+ AllocatorType (`std::allocator`), the default value for @a array_t is:
+
+ @code {.cpp}
+ std::vector<
+ basic_json, // value_type
+ std::allocator<basic_json> // allocator_type
+ >
+ @endcode
+
+ #### Limits
+
+ [RFC 7159](http://rfc7159.net/rfc7159) specifies:
+ > An implementation may set limits on the maximum depth of nesting.
+
+ In this class, the array's limit of nesting is not constraint explicitly.
+ However, a maximum depth of nesting may be introduced by the compiler or
+ runtime environment. A theoretical limit can be queried by calling the @ref
+ max_size function of a JSON array.
+
+ #### Storage
+
+ Arrays are stored as pointers in a `basic_json` type. That is, for any
+ access to array values, a pointer of type `array_t*` must be dereferenced.
+ */
+ using array_t = ArrayType<basic_json, AllocatorType<basic_json>>;
+
+ /*!
+ @brief a type for a string
+
+ [RFC 7159](http://rfc7159.net/rfc7159) describes JSON strings as follows:
+ > A string is a sequence of zero or more Unicode characters.
+
+ To store objects in C++, a type is defined by the template parameters @a
+ StringType which chooses the container (e.g., `std::string`) to use.
+
+ Unicode values are split by the JSON class into byte-sized characters
+ during deserialization.
+
+ #### Default type
+
+ With the default values for @a StringType (`std::string`), the default
+ value for @a string_t is:
+
+ @code {.cpp}
+ std::string
+ @endcode
+
+ #### String comparison
+
+ [RFC 7159](http://rfc7159.net/rfc7159) states:
+ > Software implementations are typically required to test names of object
+ > members for equality. Implementations that transform the textual
+ > representation into sequences of Unicode code units and then perform the
+ > comparison numerically, code unit by code unit, are interoperable in the
+ > sense that implementations will agree in all cases on equality or
+ > inequality of two strings. For example, implementations that compare
+ > strings with escaped characters unconverted may incorrectly find that
+ > `"a\\b"` and `"a\u005Cb"` are not equal.
+
+ This implementation is interoperable as it does compare strings code unit
+ by code unit.
+
+ #### Storage
+
+ String values are stored as pointers in a `basic_json` type. That is, for
+ any access to string values, a pointer of type `string_t*` must be
+ dereferenced.
+ */
+ using string_t = StringType;
+
+ /*!
+ @brief a type for a boolean
+
+ [RFC 7159](http://rfc7159.net/rfc7159) implicitly describes a boolean as a
+ type which differentiates the two literals `true` and `false`.
+
+ To store objects in C++, a type is defined by the template parameter @a
+ BooleanType which chooses the type to use.
+
+ #### Default type
+
+ With the default values for @a BooleanType (`bool`), the default value for
+ @a boolean_t is:
+
+ @code {.cpp}
+ bool
+ @endcode
+
+ #### Storage
+
+ Boolean values are stored directly inside a `basic_json` type.
+ */
+ using boolean_t = BooleanType;
+
+ /*!
+ @brief a type for a number (integer)
+
+ [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows:
+ > The representation of numbers is similar to that used in most programming
+ > languages. A number is represented in base 10 using decimal digits. It
+ > contains an integer component that may be prefixed with an optional minus
+ > sign, which may be followed by a fraction part and/or an exponent part.
+ > Leading zeros are not allowed. (...) Numeric values that cannot be
+ > represented in the grammar below (such as Infinity and NaN) are not
+ > permitted.
+
+ This description includes both integer and floating-point numbers. However,
+ C++ allows more precise storage if it is known whether the number is an
+ integer or a floating-point number. Therefore, two different types, @ref
+ number_integer_t and @ref number_float_t are used.
+
+ To store integer numbers in C++, a type is defined by the template
+ parameter @a NumberIntegerType which chooses the type to use.
+
+ #### Default type
+
+ With the default values for @a NumberIntegerType (`int64_t`), the default
+ value for @a number_integer_t is:
+
+ @code {.cpp}
+ int64_t
+ @endcode
+
+ #### Default behavior
+
+ - The restrictions about leading zeros is not enforced in C++. Instead,
+ leading zeros in integer literals lead to an interpretation as octal
+ number. Internally, the value will be stored as decimal number. For
+ instance, the C++ integer literal `010` will be serialized to `8`. During
+ deserialization, leading zeros yield an error.
+ - Not-a-number (NaN) values will be serialized to `null`.
+
+ #### Limits
+
+ [RFC 7159](http://rfc7159.net/rfc7159) specifies:
+ > An implementation may set limits on the range and precision of numbers.
+
+ When the default type is used, the maximal integer number that can be
+ stored is `9223372036854775807` (INT64_MAX) and the minimal integer number
+ that can be stored is `-9223372036854775808` (INT64_MIN). Integer numbers
+ that are out of range will yield over/underflow when used in a constructor.
+ During deserialization, too large or small integer numbers will be
+ automatically be stored as @ref number_float_t.
+
+ [RFC 7159](http://rfc7159.net/rfc7159) further states:
+ > Note that when such software is used, numbers that are integers and are
+ > in the range \f$[-2^{53}+1, 2^{53}-1]\f$ are interoperable in the sense
+ > that implementations will agree exactly on their numeric values.
+
+ As this range is a subrange of the exactly supported range [INT64_MIN,
+ INT64_MAX], this class's integer type is interoperable.
+
+ #### Storage
+
+ Integer number values are stored directly inside a `basic_json` type.
+ */
+ using number_integer_t = NumberIntegerType;
+
+ /*!
+ @brief a type for a number (floating-point)
+
+ [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows:
+ > The representation of numbers is similar to that used in most programming
+ > languages. A number is represented in base 10 using decimal digits. It
+ > contains an integer component that may be prefixed with an optional minus
+ > sign, which may be followed by a fraction part and/or an exponent part.
+ > Leading zeros are not allowed. (...) Numeric values that cannot be
+ > represented in the grammar below (such as Infinity and NaN) are not
+ > permitted.
+
+ This description includes both integer and floating-point numbers. However,
+ C++ allows more precise storage if it is known whether the number is an
+ integer or a floating-point number. Therefore, two different types, @ref
+ number_integer_t and @ref number_float_t are used.
+
+ To store floating-point numbers in C++, a type is defined by the template
+ parameter @a NumberFloatType which chooses the type to use.
+
+ #### Default type
+
+ With the default values for @a NumberFloatType (`double`), the default
+ value for @a number_float_t is:
+
+ @code {.cpp}
+ double
+ @endcode
+
+ #### Default behavior
+
+ - The restrictions about leading zeros is not enforced in C++. Instead,
+ leading zeros in floating-point literals will be ignored. Internally, the
+ value will be stored as decimal number. For instance, the C++
+ floating-point literal `01.2` will be serialized to `1.2`. During
+ deserialization, leading zeros yield an error.
+ - Not-a-number (NaN) values will be serialized to `null`.
+
+ #### Limits
+
+ [RFC 7159](http://rfc7159.net/rfc7159) states:
+ > This specification allows implementations to set limits on the range and
+ > precision of numbers accepted. Since software that implements IEEE
+ > 754-2008 binary64 (double precision) numbers is generally available and
+ > widely used, good interoperability can be achieved by implementations that
+ > expect no more precision or range than these provide, in the sense that
+ > implementations will approximate JSON numbers within the expected
+ > precision.
+
+ This implementation does exactly follow this approach, as it uses double
+ precision floating-point numbers. Note values smaller than
+ `-1.79769313486232e+308` and values greather than `1.79769313486232e+308`
+ will be stored as NaN internally and be serialized to `null`.
+
+ #### Storage
+
+ Floating-point number values are stored directly inside a `basic_json` type.
+ */
+ using number_float_t = NumberFloatType;
+
+ /// @}
+
+
+ ///////////////////////////
+ // JSON type enumeration //
+ ///////////////////////////
+
+ /*!
+ @brief the JSON type enumeration
+
+ This enumeration collects the different JSON types. It is internally used
+ to distinguish the stored values, and the functions is_null, is_object,
+ is_array, is_string, is_boolean, is_number, and is_discarded rely on it.
+ */
+ enum class value_t : uint8_t
+ {
+ null, ///< null value
+ object, ///< object (unordered set of name/value pairs)
+ array, ///< array (ordered collection of values)
+ string, ///< string value
+ boolean, ///< boolean value
+ number_integer, ///< number value (integer)
+ number_float, ///< number value (floating-point)
+ discarded ///< discarded by the the parser callback function
+ };
+
+
+ private:
+ /// helper for exception-safe object creation
+ template<typename T, typename... Args>
+ static T* create(Args&& ... args)
+ {
+ AllocatorType<T> alloc;
+ auto deleter = [&](T * object)
+ {
+ alloc.deallocate(object, 1);
+ };
+ std::unique_ptr<T, decltype(deleter)> object(alloc.allocate(1), deleter);
+ alloc.construct(object.get(), std::forward<Args>(args)...);
+ return object.release();
+ }
+
+ ////////////////////////
+ // JSON value storage //
+ ////////////////////////
+
+ /// a JSON value
+ union json_value
+ {
+ /// object (stored with pointer to save storage)
+ object_t* object;
+ /// array (stored with pointer to save storage)
+ array_t* array;
+ /// string (stored with pointer to save storage)
+ string_t* string;
+ /// boolean
+ boolean_t boolean;
+ /// number (integer)
+ number_integer_t number_integer;
+ /// number (floating-point)
+ number_float_t number_float;
+
+ /// default constructor (for null values)
+ json_value() noexcept = default;
+ /// constructor for booleans
+ json_value(boolean_t v) noexcept : boolean(v) {}
+ /// constructor for numbers (integer)
+ json_value(number_integer_t v) noexcept : number_integer(v) {}
+ /// constructor for numbers (floating-point)
+ json_value(number_float_t v) noexcept : number_float(v) {}
+ /// constructor for empty values of a given type
+ json_value(value_t t)
+ {
+ switch (t)
+ {
+ case (value_t::null):
+ case (value_t::discarded):
+ {
+ break;
+ }
+
+ case (value_t::object):
+ {
+ object = create<object_t>();
+ break;
+ }
+
+ case (value_t::array):
+ {
+ array = create<array_t>();
+ break;
+ }
+
+ case (value_t::string):
+ {
+ string = create<string_t>("");
+ break;
+ }
+
+ case (value_t::boolean):
+ {
+ boolean = boolean_t(false);
+ break;
+ }
+
+ case (value_t::number_integer):
+ {
+ number_integer = number_integer_t(0);
+ break;
+ }
+
+ case (value_t::number_float):
+ {
+ number_float = number_float_t(0.0);
+ break;
+ }
+ }
+ }
+
+ /// constructor for strings
+ json_value(const string_t& value)
+ {
+ string = create<string_t>(value);
+ }
+
+ /// constructor for objects
+ json_value(const object_t& value)
+ {
+ object = create<object_t>(value);
+ }
+
+ /// constructor for arrays
+ json_value(const array_t& value)
+ {
+ array = create<array_t>(value);
+ }
+ };
+
+
+ public:
+ //////////////////////////
+ // JSON parser callback //
+ //////////////////////////
+
+ /*!
+ @brief JSON callback events
+
+ This enumeration lists the parser events that can trigger calling a
+ callback function of type @ref parser_callback_t during parsing.
+ */
+ enum class parse_event_t : uint8_t
+ {
+ /// the parser read `{` and started to process a JSON object
+ object_start,
+ /// the parser read `}` and finished processing a JSON object
+ object_end,
+ /// the parser read `[` and started to process a JSON array
+ array_start,
+ /// the parser read `]` and finished processing a JSON array
+ array_end,
+ /// the parser read a key of a value in an object
+ key,
+ /// the parser finished reading a JSON value
+ value
+ };
+
+ /*!
+ @brief per-element parser callback type
+
+ With a parser callback function, the result of parsing a JSON text can be
+ influenced. When passed to @ref parse(std::istream&, parser_callback_t) or
+ @ref parse(const string_t&, parser_callback_t), it is called on certain
+ events (passed as @ref parse_event_t via parameter @a event) with a set
+ recursion depth @a depth and context JSON value @a parsed. The return value
+ of the callback function is a boolean indicating whether the element that
+ emitted the callback shall be kept or not.
+
+ We distinguish six scenarios (determined by the event type) in which the
+ callback function can be called. The following table describes the values
+ of the parameters @a depth, @a event, and @a parsed.
+
+ parameter @a event | description | parameter @a depth | parameter @a parsed
+ ------------------ | ----------- | ------------------ | -------------------
+ parse_event_t::object_start | the parser read `{` and started to process a JSON object | depth of the parent of the JSON object | a JSON value with type discarded
+ parse_event_t::key | the parser read a key of a value in an object | depth of the currently parsed JSON object | a JSON string containing the key
+ parse_event_t::object_end | the parser read `}` and finished processing a JSON object | depth of the parent of the JSON object | the parsed JSON object
+ parse_event_t::array_start | the parser read `[` and started to process a JSON array | depth of the parent of the JSON array | a JSON value with type discarded
+ parse_event_t::array_end | the parser read `]` and finished processing a JSON array | depth of the parent of the JSON array | the parsed JSON array
+ parse_event_t::value | the parser finished reading a JSON value | depth of the value | the parsed JSON value
+
+ Discarding a value (i.e., returning `false`) has different effects depending on the
+ context in which function was called:
+
+ - Discarded values in structured types are skipped. That is, the parser
+ will behave as if the discarded value was never read.
+ - In case a value outside a structured type is skipped, it is replaced with
+ `null`. This case happens if the top-level element is skipped.
+
+ @param[in] depth the depth of the recursion during parsing
+
+ @param[in] event an event of type parse_event_t indicating the context in
+ the callback function has been called
+
+ @param[in,out] parsed the current intermediate parse result; note that
+ writing to this value has no effect for parse_event_t::key events
+
+ @return Whether the JSON value which called the function during parsing
+ should be kept (`true`) or not (`false`). In the latter case, it is either
+ skipped completely or replaced by an empty discarded object.
+
+ @sa @ref parse(std::istream&, parser_callback_t) or
+ @ref parse(const string_t&, parser_callback_t) for examples
+ */
+ using parser_callback_t = std::function<bool(
+ int depth, parse_event_t event, basic_json& parsed)>;
+
+
+ //////////////////
+ // constructors //
+ //////////////////
+
+ /*!
+ @brief create an empty value with a given type
+
+ Create an empty JSON value with a given type. The value will be default
+ initialized with an empty value which depends on the type:
+
+ Value type | initial value
+ ----------- | -------------
+ null | `null`
+ boolean | `false`
+ string | `""`
+ number | `0`
+ object | `{}`
+ array | `[]`
+
+ @param[in] value the type of the value to create
+
+ @complexity Constant.
+
+ @throw std::bad_alloc if allocation for object, array, or string value
+ fails
+
+ @liveexample{The following code shows the constructor for different @ref
+ value_t values,basic_json__value_t}
+ */
+ basic_json(const value_t value)
+ : m_type(value), m_value(value)
+ {}
+
+ /*!
+ @brief create a null object (implicitly)
+
+ Create a `null` JSON value. This is the implicit version of the `null`
+ value constructor as it takes no parameters.
+
+ @complexity Constant.
+
+ @requirement This function satisfies the Container requirements:
+ - The complexity is constant.
+ - As postcondition, it holds: `basic_json().empty() == true`.
+
+ @liveexample{The following code shows the constructor for a `null` JSON
+ value.,basic_json}
+
+ @sa basic_json(std::nullptr_t)
+ */
+ basic_json() noexcept = default;
+
+ /*!
+ @brief create a null object (explicitly)
+
+ Create a `null` JSON value. This is the explicitly version of the `null`
+ value constructor as it takes a null pointer as parameter. It allows to
+ create `null` values by explicitly assigning a @c nullptr to a JSON value.
+ The passed null pointer itself is not read - it is only used to choose the
+ right constructor.
+
+ @complexity Constant.
+
+ @liveexample{The following code shows the constructor with null pointer
+ parameter.,basic_json__nullptr_t}
+
+ @sa basic_json()
+ */
+ basic_json(std::nullptr_t) noexcept
+ : basic_json(value_t::null)
+ {}
+
+ /*!
+ @brief create an object (explicit)
+
+ Create an object JSON value with a given content.
+
+ @param[in] value a value for the object
+
+ @complexity Linear in the size of the passed @a value.
+
+ @throw std::bad_alloc if allocation for object value fails
+
+ @liveexample{The following code shows the constructor with an @ref object_t
+ parameter.,basic_json__object_t}
+
+ @sa basic_json(const CompatibleObjectType&)
+ */
+ basic_json(const object_t& value)
+ : m_type(value_t::object), m_value(value)
+ {}
+
+ /*!
+ @brief create an object (implicit)
+
+ Create an object JSON value with a given content. This constructor allows
+ any type that can be used to construct values of type @ref object_t.
+ Examples include the types `std::map` and `std::unordered_map`.
+
+ @tparam CompatibleObjectType an object type whose `key_type` and
+ `value_type` is compatible to @ref object_t
+
+ @param[in] value a value for the object
+
+ @complexity Linear in the size of the passed @a value.
+
+ @throw std::bad_alloc if allocation for object value fails
+
+ @liveexample{The following code shows the constructor with several
+ compatible object type parameters.,basic_json__CompatibleObjectType}
+
+ @sa basic_json(const object_t&)
+ */
+ template <class CompatibleObjectType, typename
+ std::enable_if<
+ std::is_constructible<typename object_t::key_type, typename CompatibleObjectType::key_type>::value and
+ std::is_constructible<basic_json, typename CompatibleObjectType::mapped_type>::value, int>::type
+ = 0>
+ basic_json(const CompatibleObjectType& value)
+ : m_type(value_t::object)
+ {
+ using std::begin;
+ using std::end;
+ m_value.object = create<object_t>(begin(value), end(value));
+ }
+
+ /*!
+ @brief create an array (explicit)
+
+ Create an array JSON value with a given content.
+
+ @param[in] value a value for the array
+
+ @complexity Linear in the size of the passed @a value.
+
+ @throw std::bad_alloc if allocation for array value fails
+
+ @liveexample{The following code shows the constructor with an @ref array_t
+ parameter.,basic_json__array_t}
+
+ @sa basic_json(const CompatibleArrayType&)
+ */
+ basic_json(const array_t& value)
+ : m_type(value_t::array), m_value(value)
+ {}
+
+ /*!
+ @brief create an array (implicit)
+
+ Create an array JSON value with a given content. This constructor allows
+ any type that can be used to construct values of type @ref array_t.
+ Examples include the types `std::vector`, `std::list`, and `std::set`.
+
+ @tparam CompatibleArrayType an object type whose `value_type` is compatible
+ to @ref array_t
+
+ @param[in] value a value for the array
+
+ @complexity Linear in the size of the passed @a value.
+
+ @throw std::bad_alloc if allocation for array value fails
+
+ @liveexample{The following code shows the constructor with several
+ compatible array type parameters.,basic_json__CompatibleArrayType}
+
+ @sa basic_json(const array_t&)
+ */
+ template <class CompatibleArrayType, typename
+ std::enable_if<
+ not std::is_same<CompatibleArrayType, typename basic_json_t::iterator>::value and
+ not std::is_same<CompatibleArrayType, typename basic_json_t::const_iterator>::value and
+ not std::is_same<CompatibleArrayType, typename basic_json_t::reverse_iterator>::value and
+ not std::is_same<CompatibleArrayType, typename basic_json_t::const_reverse_iterator>::value and
+ not std::is_same<CompatibleArrayType, typename array_t::iterator>::value and
+ not std::is_same<CompatibleArrayType, typename array_t::const_iterator>::value and
+ std::is_constructible<basic_json, typename CompatibleArrayType::value_type>::value, int>::type
+ = 0>
+ basic_json(const CompatibleArrayType& value)
+ : m_type(value_t::array)
+ {
+ using std::begin;
+ using std::end;
+ m_value.array = create<array_t>(begin(value), end(value));
+ }
+
+ /*!
+ @brief create a string (explicit)
+
+ Create an string JSON value with a given content.
+
+ @param[in] value a value for the string
+
+ @complexity Linear in the size of the passed @a value.
+
+ @throw std::bad_alloc if allocation for string value fails
+
+ @liveexample{The following code shows the constructor with an @ref string_t
+ parameter.,basic_json__string_t}
+
+ @sa basic_json(const typename string_t::value_type*)
+ @sa basic_json(const CompatibleStringType&)
+ */
+ basic_json(const string_t& value)
+ : m_type(value_t::string), m_value(value)
+ {}
+
+ /*!
+ @brief create a string (explicit)
+
+ Create a string JSON value with a given content.
+
+ @param[in] value a literal value for the string
+
+ @complexity Linear in the size of the passed @a value.
+
+ @throw std::bad_alloc if allocation for string value fails
+
+ @liveexample{The following code shows the constructor with string literal
+ parameter.,basic_json__string_t_value_type}
+
+ @sa basic_json(const string_t&)
+ @sa basic_json(const CompatibleStringType&)
+ */
+ basic_json(const typename string_t::value_type* value)
+ : basic_json(string_t(value))
+ {}
+
+ /*!
+ @brief create a string (implicit)
+
+ Create a string JSON value with a given content.
+
+ @param[in] value a value for the string
+
+ @tparam CompatibleStringType an string type which is compatible to @ref
+ string_t
+
+ @complexity Linear in the size of the passed @a value.
+
+ @throw std::bad_alloc if allocation for string value fails
+
+ @liveexample{The following code shows the construction of a string value
+ from a compatible type.,basic_json__CompatibleStringType}
+
+ @sa basic_json(const string_t&)
+ */
+ template <class CompatibleStringType, typename
+ std::enable_if<
+ std::is_constructible<string_t, CompatibleStringType>::value, int>::type
+ = 0>
+ basic_json(const CompatibleStringType& value)
+ : basic_json(string_t(value))
+ {}
+
+ /*!
+ @brief create a boolean (explicit)
+
+ Creates a JSON boolean type from a given value.
+
+ @param[in] value a boolean value to store
+
+ @complexity Constant.
+
+ @liveexample{The example below demonstrates boolean
+ values.,basic_json__boolean_t}
+ */
+ basic_json(boolean_t value)
+ : m_type(value_t::boolean), m_value(value)
+ {}
+
+ /*!
+ @brief create an integer number (explicit)
+
+ Create an interger number JSON value with a given content.
+
+ @tparam T helper type to compare number_integer_t and int (not visible in)
+ the interface.
+
+ @param[in] value an integer to create a JSON number from
+
+ @note This constructor would have the same signature as @ref
+ basic_json(const int value), so we need to switch this one off in case
+ number_integer_t is the same as int. This is done via the helper type @a T.
+
+ @complexity Constant.
+
+ @liveexample{The example below shows the construction of a JSON integer
+ number value.,basic_json__number_integer_t}
+
+ @sa basic_json(const int)
+ */
+ template<typename T,
+ typename std::enable_if<
+ not (std::is_same<T, int>::value)
+ and std::is_same<T, number_integer_t>::value
+ , int>::type = 0>
+ basic_json(const number_integer_t value)
+ : m_type(value_t::number_integer), m_value(value)
+ {}
+
+ /*!
+ @brief create an integer number from an enum type (explicit)
+
+ Create an integer number JSON value with a given content.
+
+ @param[in] value an integer to create a JSON number from
+
+ @note This constructor allows to pass enums directly to a constructor. As
+ C++ has no way of specifying the type of an anonymous enum explicitly, we
+ can only rely on the fact that such values implicitly convert to int. As
+ int may already be the same type of number_integer_t, we may need to switch
+ off the constructor @ref basic_json(const number_integer_t).
+
+ @complexity Constant.
+
+ @liveexample{The example below shows the construction of a JSON integer
+ number value from an anonymous enum.,basic_json__const_int}
+
+ @sa basic_json(const number_integer_t)
+ */
+ basic_json(const int value)
+ : m_type(value_t::number_integer),
+ m_value(static_cast<number_integer_t>(value))
+ {}
+
+ /*!
+ @brief create an integer number (implicit)
+
+ Create an integer number JSON value with a given content. This constructor
+ allows any type that can be used to construct values of type @ref
+ number_integer_t. Examples may include the types `int`, `int32_t`, or
+ `short`.
+
+ @tparam CompatibleNumberIntegerType an integer type which is compatible to
+ @ref number_integer_t.
+
+ @param[in] value an integer to create a JSON number from
+
+ @complexity Constant.
+
+ @liveexample{The example below shows the construction of several JSON
+ integer number values from compatible
+ types.,basic_json__CompatibleIntegerNumberType}
+
+ @sa basic_json(const number_integer_t)
+ */
+ template<typename CompatibleNumberIntegerType, typename
+ std::enable_if<
+ std::is_constructible<number_integer_t, CompatibleNumberIntegerType>::value and
+ std::numeric_limits<CompatibleNumberIntegerType>::is_integer, CompatibleNumberIntegerType>::type
+ = 0>
+ basic_json(const CompatibleNumberIntegerType value) noexcept
+ : m_type(value_t::number_integer),
+ m_value(static_cast<number_integer_t>(value))
+ {}
+
+ /*!
+ @brief create a floating-point number (explicit)
+
+ Create a floating-point number JSON value with a given content.
+
+ @param[in] value a floating-point value to create a JSON number from
+
+ @note RFC 7159 <http://www.rfc-editor.org/rfc/rfc7159.txt>, section 6
+ disallows NaN values:
+ > Numeric values that cannot be represented in the grammar below (such
+ > as Infinity and NaN) are not permitted.
+ In case the parameter @a value is not a number, a JSON null value is
+ created instead.
+
+ @complexity Constant.
+
+ @liveexample{The following example creates several floating-point
+ values.,basic_json__number_float_t}
+ */
+ basic_json(const number_float_t value)
+ : m_type(value_t::number_float), m_value(value)
+ {
+ // replace infinity and NAN by null
+ if (not std::isfinite(value))
+ {
+ m_type = value_t::null;
+ m_value = json_value();
+ }
+ }
+
+ /*!
+ @brief create an floating-point number (implicit)
+
+ Create an floating-point number JSON value with a given content. This
+ constructor allows any type that can be used to construct values of type
+ @ref number_float_t. Examples may include the types `float`.
+
+ @tparam CompatibleNumberFloatType a floating-point type which is compatible
+ to @ref number_float_t.
+
+ @param[in] value a floating-point to create a JSON number from
+
+ @note RFC 7159 <http://www.rfc-editor.org/rfc/rfc7159.txt>, section 6
+ disallows NaN values:
+ > Numeric values that cannot be represented in the grammar below (such
+ > as Infinity and NaN) are not permitted.
+ In case the parameter @a value is not a number, a JSON null value is
+ created instead.
+
+ @complexity Constant.
+
+ @liveexample{The example below shows the construction of several JSON
+ floating-point number values from compatible
+ types.,basic_json__CompatibleNumberFloatType}
+
+ @sa basic_json(const number_float_t)
+ */
+ template<typename CompatibleNumberFloatType, typename = typename
+ std::enable_if<
+ std::is_constructible<number_float_t, CompatibleNumberFloatType>::value and
+ std::is_floating_point<CompatibleNumberFloatType>::value>::type
+ >
+ basic_json(const CompatibleNumberFloatType value) noexcept
+ : basic_json(number_float_t(value))
+ {}
+
+ /*!
+ @brief create a container (array or object) from an initializer list
+
+ Creates a JSON value of type array or object from the passed initializer
+ list @a init. In case @a type_deduction is `true` (default), the type of
+ the JSON value to be created is deducted from the initializer list @a init
+ according to the following rules:
+
+ 1. If the list is empty, an empty JSON object value `{}` is created.
+ 2. If the list consists of pairs whose first element is a string, a JSON
+ object value is created where the first elements of the pairs are treated
+ as keys and the second elements are as values.
+ 3. In all other cases, an array is created.
+
+ The rules aim to create the best fit between a C++ initializer list and
+ JSON values. The ratioinale is as follows:
+
+ 1. The empty initializer list is written as `{}` which is exactly an empty
+ JSON object.
+ 2. C++ has now way of describing mapped types other than to list a list of
+ pairs. As JSON requires that keys must be of type string, rule 2 is the
+ weakest constraint one can pose on initializer lists to interpret them as
+ an object.
+ 3. In all other cases, the initializer list could not be interpreted as
+ JSON object type, so interpreting it as JSON array type is safe.
+
+ With the rules described above, the following JSON values cannot be
+ expressed by an initializer list:
+
+ - the empty array (`[]`): use @ref array(std::initializer_list<basic_json>)
+ with an empty initializer list in this case
+ - arrays whose elements satisfy rule 2: use @ref
+ array(std::initializer_list<basic_json>) with the same initializer list
+ in this case
+
+ @note When used without parentheses around an empty initializer list, @ref
+ basic_json() is called instead of this function, yielding the JSON null
+ value.
+
+ @param[in] init initializer list with JSON values
+
+ @param[in] type_deduction internal parameter; when set to `true`, the type
+ of the JSON value is deducted from the initializer list @a init; when set
+ to `false`, the type provided via @a manual_type is forced. This mode is
+ used by the functions @ref array(std::initializer_list<basic_json>) and
+ @ref object(std::initializer_list<basic_json>).
+
+ @param[in] manual_type internal parameter; when @a type_deduction is set to
+ `false`, the created JSON value will use the provided type (only @ref
+ value_t::array and @ref value_t::object are valid); when @a type_deduction
+ is set to `true`, this parameter has no effect
+
+ @throw std::domain_error if @a type_deduction is `false`, @a manual_type is
+ `value_t::object`, but @a init contains an element which is not a pair
+ whose first element is a string
+
+ @complexity Linear in the size of the initializer list @a init.
+
+ @liveexample{The example below shows how JSON values are created from
+ initializer lists,basic_json__list_init_t}
+
+ @sa basic_json array(std::initializer_list<basic_json>) - create a JSON
+ array value from an initializer list
+ @sa basic_json object(std::initializer_list<basic_json>) - create a JSON
+ object value from an initializer list
+ */
+ basic_json(std::initializer_list<basic_json> init,
+ bool type_deduction = true,
+ value_t manual_type = value_t::array)
+ {
+ // the initializer list could describe an object
+ bool is_object = true;
+
+ // check if each element is an array with two elements whose first element
+ // is a string
+ for (const auto& element : init)
+ {
+ if (element.m_type != value_t::array or element.size() != 2
+ or element[0].m_type != value_t::string)
+ {
+ // we found an element that makes it impossible to use the
+ // initializer list as object
+ is_object = false;
+ break;
+ }
+ }
+
+ // adjust type if type deduction is not wanted
+ if (not type_deduction)
+ {
+ // if array is wanted, do not create an object though possible
+ if (manual_type == value_t::array)
+ {
+ is_object = false;
+ }
+
+ // if object is wanted but impossible, throw an exception
+ if (manual_type == value_t::object and not is_object)
+ {
+ throw std::domain_error("cannot create object from initializer list");
+ }
+ }
+
+ if (is_object)
+ {
+ // the initializer list is a list of pairs -> create object
+ m_type = value_t::object;
+ m_value = value_t::object;
+
+ for (auto& element : init)
+ {
+ m_value.object->emplace(std::move(*(element[0].m_value.string)), std::move(element[1]));
+ }
+ }
+ else
+ {
+ // the initializer list describes an array -> create array
+ m_type = value_t::array;
+ m_value.array = create<array_t>(std::move(init));
+ }
+ }
+
+ /*!
+ @brief explicitly create an array from an initializer list
+
+ Creates a JSON array value from a given initializer list. That is, given a
+ list of values `a, b, c`, creates the JSON value `[a, b, c]`. If the
+ initializer list is empty, the empty array `[]` is created.
+
+ @note This function is only needed to express two edge cases that cannot be
+ realized with the initializer list constructor (@ref
+ basic_json(std::initializer_list<basic_json>, bool, value_t)). These cases
+ are:
+ 1. creating an array whose elements are all pairs whose first element is a
+ string - in this case, the initializer list constructor would create an
+ object, taking the first elements as keys
+ 2. creating an empty array - passing the empty initializer list to the
+ initializer list constructor yields an empty object
+
+ @param[in] init initializer list with JSON values to create an array from
+ (optional)
+
+ @return JSON array value
+
+ @complexity Linear in the size of @a init.
+
+ @liveexample{The following code shows an example for the @ref array
+ function.,array}
+
+ @sa basic_json(std::initializer_list<basic_json>, bool, value_t) - create a
+ JSON value from an initializer list
+ @sa basic_json object(std::initializer_list<basic_json>) - create a JSON
+ object value from an initializer list
+ */
+ static basic_json array(std::initializer_list<basic_json> init =
+ std::initializer_list<basic_json>())
+ {
+ return basic_json(init, false, value_t::array);
+ }
+
+ /*!
+ @brief explicitly create an object from an initializer list
+
+ Creates a JSON object value from a given initializer list. The initializer
+ lists elements must be pairs, and their first elments must be strings. If
+ the initializer list is empty, the empty object `{}` is created.
+
+ @note This function is only added for symmetry reasons. In contrast to the
+ related function @ref basic_json array(std::initializer_list<basic_json>),
+ there are no cases which can only be expressed by this function. That is,
+ any initializer list @a init can also be passed to the initializer list
+ constructor @ref basic_json(std::initializer_list<basic_json>, bool,
+ value_t).
+
+ @param[in] init initializer list to create an object from (optional)
+
+ @return JSON object value
+
+ @throw std::domain_error if @a init is not a pair whose first elements are
+ strings; thrown by @ref basic_json(std::initializer_list<basic_json>, bool,
+ value_t)
+
+ @complexity Linear in the size of @a init.
+
+ @liveexample{The following code shows an example for the @ref object
+ function.,object}
+
+ @sa basic_json(std::initializer_list<basic_json>, bool, value_t) - create a
+ JSON value from an initializer list
+ @sa basic_json array(std::initializer_list<basic_json>) - create a JSON
+ array value from an initializer list
+ */
+ static basic_json object(std::initializer_list<basic_json> init =
+ std::initializer_list<basic_json>())
+ {
+ return basic_json(init, false, value_t::object);
+ }
+
+ /*!
+ @brief construct an array with count copies of given value
+
+ Constructs a JSON array value by creating @a count copies of a passed
+ value. In case @a count is `0`, an empty array is created. As postcondition,
+ `std::distance(begin(),end()) == count` holds.
+
+ @param[in] count the number of JSON copies of @a value to create
+ @param[in] value the JSON value to copy
+
+ @complexity Linear in @a count.
+
+ @liveexample{The following code shows examples for the @ref
+ basic_json(size_type\, const basic_json&)
+ constructor.,basic_json__size_type_basic_json}
+ */
+ basic_json(size_type count, const basic_json& value)
+ : m_type(value_t::array)
+ {
+ m_value.array = create<array_t>(count, value);
+ }
+
+ /*!
+ @brief construct a JSON container given an iterator range
+
+ Constructs the JSON value with the contents of the range `[first, last)`.
+ The semantics depends on the different types a JSON value can have:
+ - In case of primitive types (number, boolean, or string), @a first must
+ be `begin()` and @a last must be `end()`. In this case, the value is
+ copied. Otherwise, std::out_of_range is thrown.
+ - In case of structured types (array, object), the constructor behaves
+ as similar versions for `std::vector`.
+ - In case of a null type, std::domain_error is thrown.
+
+ @tparam InputIT an input iterator type (@ref iterator or @ref
+ const_iterator)
+
+ @param[in] first begin of the range to copy from (included)
+ @param[in] last end of the range to copy from (excluded)
+
+ @throw std::domain_error if iterators are not compatible; that is, do not
+ belong to the same JSON value
+ @throw std::out_of_range if iterators are for a primitive type (number,
+ boolean, or string) where an out of range error can be detected easily
+ @throw std::bad_alloc if allocation for object, array, or string fails
+ @throw std::domain_error if called with a null value
+
+ @complexity Linear in distance between @a first and @a last.
+
+ @liveexample{The example below shows several ways to create JSON values by
+ specifying a subrange with iterators.,basic_json__InputIt_InputIt}
+ */
+ template <class InputIT, typename
+ std::enable_if<
+ std::is_same<InputIT, typename basic_json_t::iterator>::value or
+ std::is_same<InputIT, typename basic_json_t::const_iterator>::value
+ , int>::type
+ = 0>
+ basic_json(InputIT first, InputIT last) : m_type(first.m_object->m_type)
+ {
+ // make sure iterator fits the current value
+ if (first.m_object != last.m_object)
+ {
+ throw std::domain_error("iterators are not compatible");
+ }
+
+ // check if iterator range is complete for primitive values
+ switch (m_type)
+ {
+ case value_t::number_integer:
+ case value_t::number_float:
+ case value_t::boolean:
+ case value_t::string:
+ {
+ if (not first.m_it.primitive_iterator.is_begin() or not last.m_it.primitive_iterator.is_end())
+ {
+ throw std::out_of_range("iterators out of range");
+ }
+ break;
+ }
+
+ default:
+ {
+ break;
+ }
+ }
+
+ switch (m_type)
+ {
+ case value_t::number_integer:
+ {
+ m_value.number_integer = first.m_object->m_value.number_integer;
+ break;
+ }
+
+ case value_t::number_float:
+ {
+ m_value.number_float = first.m_object->m_value.number_float;
+ break;
+ }
+
+ case value_t::boolean:
+ {
+ m_value.boolean = first.m_object->m_value.boolean;
+ break;
+ }
+
+ case value_t::string:
+ {
+ m_value = *first.m_object->m_value.string;
+ break;
+ }
+
+ case value_t::object:
+ {
+ m_value.object = create<object_t>(first.m_it.object_iterator, last.m_it.object_iterator);
+ break;
+ }
+
+ case value_t::array:
+ {
+ m_value.array = create<array_t>(first.m_it.array_iterator, last.m_it.array_iterator);
+ break;
+ }
+
+ default:
+ {
+ throw std::domain_error("cannot use construct with iterators from " + first.m_object->type_name());
+ }
+ }
+ }
+
+ ///////////////////////////////////////
+ // other constructors and destructor //
+ ///////////////////////////////////////
+
+ /*!
+ @brief copy constructor
+
+ Creates a copy of a given JSON value.
+
+ @param[in] other the JSON value to copy
+
+ @complexity Linear in the size of @a other.
+
+ @requirement This function satisfies the Container requirements:
+ - The complexity is linear.
+ - As postcondition, it holds: `other == basic_json(other)`.
+
+ @throw std::bad_alloc if allocation for object, array, or string fails.
+
+ @liveexample{The following code shows an example for the copy
+ constructor.,basic_json__basic_json}
+ */
+ basic_json(const basic_json& other)
+ : m_type(other.m_type)
+ {
+ switch (m_type)
+ {
+ case (value_t::null):
+ case (value_t::discarded):
+ {
+ break;
+ }
+
+ case (value_t::object):
+ {
+ m_value = *other.m_value.object;
+ break;
+ }
+
+ case (value_t::array):
+ {
+ m_value = *other.m_value.array;
+ break;
+ }
+
+ case (value_t::string):
+ {
+ m_value = *other.m_value.string;
+ break;
+ }
+
+ case (value_t::boolean):
+ {
+ m_value = other.m_value.boolean;
+ break;
+ }
+
+ case (value_t::number_integer):
+ {
+ m_value = other.m_value.number_integer;
+ break;
+ }
+
+ case (value_t::number_float):
+ {
+ m_value = other.m_value.number_float;
+ break;
+ }
+ }
+ }
+
+ /*!
+ @brief move constructor
+
+ Move constructor. Constructs a JSON value with the contents of the given
+ value @a other using move semantics. It "steals" the resources from @a
+ other and leaves it as JSON null value.
+
+ @param[in,out] other value to move to this object
+
+ @post @a other is a JSON null value
+
+ @complexity Constant.
+
+ @liveexample{The code below shows the move constructor explicitly called
+ via std::move.,basic_json__moveconstructor}
+ */
+ basic_json(basic_json&& other) noexcept
+ : m_type(std::move(other.m_type)),
+ m_value(std::move(other.m_value))
+ {
+ // invalidate payload
+ other.m_type = value_t::null;
+ other.m_value = {};
+ }
+
+ /*!
+ @brief copy assignment
+
+ Copy assignment operator. Copies a JSON value via the "copy and swap"
+ strategy: It is expressed in terms of the copy constructor, destructor, and
+ the swap() member function.
+
+ @param[in] other value to copy from
+
+ @complexity Linear.
+
+ @requirement This function satisfies the Container requirements:
+ - The complexity is linear.
+
+ @liveexample{The code below shows and example for the copy assignment. It
+ creates a copy of value `a` which is then swapped with `b`. Finally\, the
+ copy of `a` (which is the null value after the swap) is
+ destroyed.,basic_json__copyassignment}
+ */
+ reference& operator=(basic_json other) noexcept (
+ std::is_nothrow_move_constructible<value_t>::value and
+ std::is_nothrow_move_assignable<value_t>::value and
+ std::is_nothrow_move_constructible<json_value>::value and
+ std::is_nothrow_move_assignable<json_value>::value
+ )
+ {
+ using std::swap;
+ swap(m_type, other.m_type);
+ swap(m_value, other.m_value);
+ return *this;
+ }
+
+ /*!
+ @brief destructor
+
+ Destroys the JSON value and frees all allocated memory.
+
+ @complexity Linear.
+
+ @requirement This function satisfies the Container requirements:
+ - The complexity is linear.
+ - All stored elements are destroyed and all memory is freed.
+ */
+ ~basic_json()
+ {
+ switch (m_type)
+ {
+ case (value_t::object):
+ {
+ AllocatorType<object_t> alloc;
+ alloc.destroy(m_value.object);
+ alloc.deallocate(m_value.object, 1);
+ break;
+ }
+
+ case (value_t::array):
+ {
+ AllocatorType<array_t> alloc;
+ alloc.destroy(m_value.array);
+ alloc.deallocate(m_value.array, 1);
+ break;
+ }
+
+ case (value_t::string):
+ {
+ AllocatorType<string_t> alloc;
+ alloc.destroy(m_value.string);
+ alloc.deallocate(m_value.string, 1);
+ break;
+ }
+
+ default:
+ {
+ // all other types need no specific destructor
+ break;
+ }
+ }
+ }
+
+
+ public:
+ ///////////////////////
+ // object inspection //
+ ///////////////////////
+
+ /// @name object inspection
+ /// @{
+
+ /*!
+ @brief serialization
+
+ Serialization function for JSON values. The function tries to mimick
+ Python's @p json.dumps() function, and currently supports its @p indent
+ parameter.
+
+ @param[in] indent if indent is nonnegative, then array elements and object
+ members will be pretty-printed with that indent level. An indent level of 0
+ will only insert newlines. -1 (the default) selects the most compact
+ representation
+
+ @return string containing the serialization of the JSON value
+
+ @complexity Linear.
+
+ @liveexample{The following example shows the effect of different @a indent
+ parameters to the result of the serializaion.,dump}
+
+ @see https://docs.python.org/2/library/json.html#json.dump
+ */
+ string_t dump(const int indent = -1) const
+ {
+ std::stringstream ss;
+
+ if (indent >= 0)
+ {
+ dump(ss, true, static_cast<unsigned int>(indent));
+ }
+ else
+ {
+ dump(ss, false, 0);
+ }
+
+ return ss.str();
+ }
+
+ /*!
+ @brief return the type of the JSON value (explicit)
+
+ Return the type of the JSON value as a value from the @ref value_t
+ enumeration.
+
+ @return the type of the JSON value
+
+ @complexity Constant.
+
+ @liveexample{The following code exemplifies @ref type() for all JSON
+ types.,type}
+ */
+ value_t type() const noexcept
+ {
+ return m_type;
+ }
+
+ /*!
+ @brief return whether type is primitive
+
+ This function returns true iff the JSON type is primitive (string, number,
+ boolean, or null).
+
+ @return `true` if type is primitive (string, number, boolean, or null),
+ `false` otherwise.
+
+ @complexity Constant.
+
+ @liveexample{The following code exemplifies @ref is_primitive for all JSON
+ types.,is_primitive}
+ */
+ bool is_primitive() const noexcept
+ {
+ return is_null() or is_string() or is_boolean() or is_number();
+ }
+
+ /*!
+ @brief return whether type is structured
+
+ This function returns true iff the JSON type is structured (array or
+ object).
+
+ @return `true` if type is structured (array or object), `false` otherwise.
+
+ @complexity Constant.
+
+ @liveexample{The following code exemplifies @ref is_structured for all JSON
+ types.,is_structured}
+ */
+ bool is_structured() const noexcept
+ {
+ return is_array() or is_object();
+ }
+
+ /*!
+ @brief return whether value is null
+
+ This function returns true iff the JSON value is null.
+
+ @return `true` if type is null, `false` otherwise.
+
+ @complexity Constant.
+
+ @liveexample{The following code exemplifies @ref is_null for all JSON
+ types.,is_null}
+ */
+ bool is_null() const noexcept
+ {
+ return m_type == value_t::null;
+ }
+
+ /*!
+ @brief return whether value is a boolean
+
+ This function returns true iff the JSON value is a boolean.
+
+ @return `true` if type is boolean, `false` otherwise.
+
+ @complexity Constant.
+
+ @liveexample{The following code exemplifies @ref is_boolean for all JSON
+ types.,is_boolean}
+ */
+ bool is_boolean() const noexcept
+ {
+ return m_type == value_t::boolean;
+ }
+
+ /*!
+ @brief return whether value is a number
+
+ This function returns true iff the JSON value is a number. This includes
+ both integer and floating-point values.
+
+ @return `true` if type is number, `false` otherwise.
+
+ @complexity Constant.
+
+ @liveexample{The following code exemplifies @ref is_number for all JSON
+ types.,is_number}
+ */
+ bool is_number() const noexcept
+ {
+ return is_number_integer() or is_number_float();
+ }
+
+ /*!
+ @brief return whether value is an integer number
+
+ This function returns true iff the JSON value is an integer number. This
+ excludes floating-point values.
+
+ @return `true` if type is an integer number, `false` otherwise.
+
+ @complexity Constant.
+
+ @liveexample{The following code exemplifies @ref is_number_integer for all
+ JSON types.,is_number_integer}
+ */
+ bool is_number_integer() const noexcept
+ {
+ return m_type == value_t::number_integer;
+ }
+
+ /*!
+ @brief return whether value is a floating-point number
+
+ This function returns true iff the JSON value is a floating-point number.
+ This excludes integer values.
+
+ @return `true` if type is a floating-point number, `false` otherwise.
+
+ @complexity Constant.
+
+ @liveexample{The following code exemplifies @ref is_number_float for all
+ JSON types.,is_number_float}
+ */
+ bool is_number_float() const noexcept
+ {
+ return m_type == value_t::number_float;
+ }
+
+ /*!
+ @brief return whether value is an object
+
+ This function returns true iff the JSON value is an object.
+
+ @return `true` if type is object, `false` otherwise.
+
+ @complexity Constant.
+
+ @liveexample{The following code exemplifies @ref is_object for all JSON
+ types.,is_object}
+ */
+ bool is_object() const noexcept
+ {
+ return m_type == value_t::object;
+ }
+
+ /*!
+ @brief return whether value is an array
+
+ This function returns true iff the JSON value is an array.
+
+ @return `true` if type is array, `false` otherwise.
+
+ @complexity Constant.
+
+ @liveexample{The following code exemplifies @ref is_array for all JSON
+ types.,is_array}
+ */
+ bool is_array() const noexcept
+ {
+ return m_type == value_t::array;
+ }
+
+ /*!
+ @brief return whether value is a string
+
+ This function returns true iff the JSON value is a string.
+
+ @return `true` if type is string, `false` otherwise.
+
+ @complexity Constant.
+
+ @liveexample{The following code exemplifies @ref is_string for all JSON
+ types.,is_string}
+ */
+ bool is_string() const noexcept
+ {
+ return m_type == value_t::string;
+ }
+
+ /*!
+ @brief return whether value is discarded
+
+ This function returns true iff the JSON value was discarded during parsing
+ with a callback function (see @ref parser_callback_t).
+
+ @note This function will always be `false` for JSON values after parsing.
+ That is, discarded values can only occur during parsing, but will be
+ removed when inside a structured value or replaced by null in other cases.
+
+ @return `true` if type is discarded, `false` otherwise.
+
+ @complexity Constant.
+
+ @liveexample{The following code exemplifies @ref is_discarded for all JSON
+ types.,is_discarded}
+ */
+ bool is_discarded() const noexcept
+ {
+ return m_type == value_t::discarded;
+ }
+
+ /*!
+ @brief return the type of the JSON value (implicit)
+
+ Implicitly return the type of the JSON value as a value from the @ref
+ value_t enumeration.
+
+ @return the type of the JSON value
+
+ @complexity Constant.
+
+ @liveexample{The following code exemplifies the value_t operator for all
+ JSON types.,operator__value_t}
+ */
+ operator value_t() const noexcept
+ {
+ return m_type;
+ }
+
+ /// @}
+
+ private:
+ //////////////////
+ // value access //
+ //////////////////
+
+ /// get an object (explicit)
+ template <class T, typename
+ std::enable_if<
+ std::is_convertible<typename object_t::key_type, typename T::key_type>::value and
+ std::is_convertible<basic_json_t, typename T::mapped_type>::value
+ , int>::type = 0>
+ T get_impl(T*) const
+ {
+ switch (m_type)
+ {
+ case (value_t::object):
+ {
+ return T(m_value.object->begin(), m_value.object->end());
+ }
+ default:
+ {
+ throw std::domain_error("type must be object, but is " + type_name());
+ }
+ }
+ }
+
+ /// get an object (explicit)
+ object_t get_impl(object_t*) const
+ {
+ switch (m_type)
+ {
+ case (value_t::object):
+ {
+ return *(m_value.object);
+ }
+ default:
+ {
+ throw std::domain_error("type must be object, but is " + type_name());
+ }
+ }
+ }
+
+ /// get an array (explicit)
+ template <class T, typename
+ std::enable_if<
+ std::is_convertible<basic_json_t, typename T::value_type>::value and
+ not std::is_same<basic_json_t, typename T::value_type>::value and
+ not std::is_arithmetic<T>::value and
+ not std::is_convertible<std::string, T>::value and
+ not has_mapped_type<T>::value
+ , int>::type = 0>
+ T get_impl(T*) const
+ {
+ switch (m_type)
+ {
+ case (value_t::array):
+ {
+ T to_vector;
+ std::transform(m_value.array->begin(), m_value.array->end(),
+ std::inserter(to_vector, to_vector.end()), [](basic_json i)
+ {
+ return i.get<typename T::value_type>();
+ });
+ return to_vector;
+ }
+ default:
+ {
+ throw std::domain_error("type must be array, but is " + type_name());
+ }
+ }
+ }
+
+ /// get an array (explicit)
+ template <class T, typename
+ std::enable_if<
+ std::is_convertible<basic_json_t, T>::value and
+ not std::is_same<basic_json_t, T>::value
+ , int>::type = 0>
+ std::vector<T> get_impl(std::vector<T>*) const
+ {
+ switch (m_type)
+ {
+ case (value_t::array):
+ {
+ std::vector<T> to_vector;
+ to_vector.reserve(m_value.array->size());
+ std::transform(m_value.array->begin(), m_value.array->end(),
+ std::inserter(to_vector, to_vector.end()), [](basic_json i)
+ {
+ return i.get<T>();
+ });
+ return to_vector;
+ }
+ default:
+ {
+ throw std::domain_error("type must be array, but is " + type_name());
+ }
+ }
+ }
+
+ /// get an array (explicit)
+ template <class T, typename
+ std::enable_if<
+ std::is_same<basic_json, typename T::value_type>::value and
+ not has_mapped_type<T>::value
+ , int>::type = 0>
+ T get_impl(T*) const
+ {
+ switch (m_type)
+ {
+ case (value_t::array):
+ {
+ return T(m_value.array->begin(), m_value.array->end());
+ }
+ default:
+ {
+ throw std::domain_error("type must be array, but is " + type_name());
+ }
+ }
+ }
+
+ /// get an array (explicit)
+ array_t get_impl(array_t*) const
+ {
+ switch (m_type)
+ {
+ case (value_t::array):
+ {
+ return *(m_value.array);
+ }
+ default:
+ {
+ throw std::domain_error("type must be array, but is " + type_name());
+ }
+ }
+ }
+
+ /// get a string (explicit)
+ template <typename T, typename
+ std::enable_if<
+ std::is_convertible<string_t, T>::value
+ , int>::type = 0>
+ T get_impl(T*) const
+ {
+ switch (m_type)
+ {
+ case (value_t::string):
+ {
+ return *m_value.string;
+ }
+ default:
+ {
+ throw std::domain_error("type must be string, but is " + type_name());
+ }
+ }
+ }
+
+ /// get a number (explicit)
+ template<typename T, typename
+ std::enable_if<
+ std::is_arithmetic<T>::value
+ , int>::type = 0>
+ T get_impl(T*) const
+ {
+ switch (m_type)
+ {
+ case (value_t::number_integer):
+ {
+ return static_cast<T>(m_value.number_integer);
+ }
+ case (value_t::number_float):
+ {
+ return static_cast<T>(m_value.number_float);
+ }
+ default:
+ {
+ throw std::domain_error("type must be number, but is " + type_name());
+ }
+ }
+ }
+
+ /// get a boolean (explicit)
+ boolean_t get_impl(boolean_t*) const
+ {
+ switch (m_type)
+ {
+ case (value_t::boolean):
+ {
+ return m_value.boolean;
+ }
+ default:
+ {
+ throw std::domain_error("type must be boolean, but is " + type_name());
+ }
+ }
+ }
+
+ /// get a pointer to the value (object)
+ object_t* get_impl_ptr(object_t*) noexcept
+ {
+ return is_object() ? m_value.object : nullptr;
+ }
+
+ /// get a pointer to the value (object)
+ const object_t* get_impl_ptr(const object_t*) const noexcept
+ {
+ return is_object() ? m_value.object : nullptr;
+ }
+
+ /// get a pointer to the value (array)
+ array_t* get_impl_ptr(array_t*) noexcept
+ {
+ return is_array() ? m_value.array : nullptr;
+ }
+
+ /// get a pointer to the value (array)
+ const array_t* get_impl_ptr(const array_t*) const noexcept
+ {
+ return is_array() ? m_value.array : nullptr;
+ }
+
+ /// get a pointer to the value (string)
+ string_t* get_impl_ptr(string_t*) noexcept
+ {
+ return is_string() ? m_value.string : nullptr;
+ }
+
+ /// get a pointer to the value (string)
+ const string_t* get_impl_ptr(const string_t*) const noexcept
+ {
+ return is_string() ? m_value.string : nullptr;
+ }
+
+ /// get a pointer to the value (boolean)
+ boolean_t* get_impl_ptr(boolean_t*) noexcept
+ {
+ return is_boolean() ? &m_value.boolean : nullptr;
+ }
+
+ /// get a pointer to the value (boolean)
+ const boolean_t* get_impl_ptr(const boolean_t*) const noexcept
+ {
+ return is_boolean() ? &m_value.boolean : nullptr;
+ }
+
+ /// get a pointer to the value (integer number)
+ number_integer_t* get_impl_ptr(number_integer_t*) noexcept
+ {
+ return is_number_integer() ? &m_value.number_integer : nullptr;
+ }
+
+ /// get a pointer to the value (integer number)
+ const number_integer_t* get_impl_ptr(const number_integer_t*) const noexcept
+ {
+ return is_number_integer() ? &m_value.number_integer : nullptr;
+ }
+
+ /// get a pointer to the value (floating-point number)
+ number_float_t* get_impl_ptr(number_float_t*) noexcept
+ {
+ return is_number_float() ? &m_value.number_float : nullptr;
+ }
+
+ /// get a pointer to the value (floating-point number)
+ const number_float_t* get_impl_ptr(const number_float_t*) const noexcept
+ {
+ return is_number_float() ? &m_value.number_float : nullptr;
+ }
+
+ public:
+
+ /// @name value access
+ /// @{
+
+ /*!
+ @brief get a value (explicit)
+
+ Explicit type conversion between the JSON value and a compatible value.
+
+ @tparam ValueType non-pointer type compatible to the JSON value, for
+ instance `int` for JSON integer numbers, `bool` for JSON booleans, or
+ `std::vector` types for JSON arrays
+
+ @return copy of the JSON value, converted to type @a ValueType
+
+ @throw std::domain_error in case passed type @a ValueType is incompatible
+ to JSON
+
+ @complexity Linear in the size of the JSON value.
+
+ @liveexample{The example below shows serveral conversions from JSON values
+ to other types. There a few things to note: (1) Floating-point numbers can
+ be converted to integers\, (2) A JSON array can be converted to a standard
+ `std::vector<short>`\, (3) A JSON object can be converted to C++
+ assiciative containers such as `std::unordered_map<std::string\,
+ json>`.,get__ValueType_const}
+
+ @internal
+ The idea of using a casted null pointer to choose the correct
+ implementation is from <http://stackoverflow.com/a/8315197/266378>.
+ @endinternal
+
+ @sa @ref operator ValueType() const for implicit conversion
+ @sa @ref get() for pointer-member access
+ */
+ template<typename ValueType, typename
+ std::enable_if<
+ not std::is_pointer<ValueType>::value
+ , int>::type = 0>
+ ValueType get() const
+ {
+ return get_impl(static_cast<ValueType*>(nullptr));
+ }
+
+ /*!
+ @brief get a pointer value (explicit)
+
+ Explicit pointer access to the internally stored JSON value. No copies are
+ made.
+
+ @warning Writing data to the pointee of the result yields an undefined
+ state.
+
+ @tparam PointerType pointer type; must be a pointer to @ref array_t, @ref
+ object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, or @ref
+ number_float_t.
+
+ @return pointer to the internally stored JSON value if the requested pointer
+ type @a PointerType fits to the JSON value; `nullptr` otherwise
+
+ @complexity Constant.
+
+ @liveexample{The example below shows how pointers to internal values of a
+ JSON value can be requested. Note that no type conversions are made and a
+ `nullptr` is returned if the value and the requested pointer type does not
+ match.,get__PointerType}
+
+ @sa @ref get_ptr() for explicit pointer-member access
+ */
+ template<typename PointerType, typename
+ std::enable_if<
+ std::is_pointer<PointerType>::value
+ , int>::type = 0>
+ PointerType get() noexcept
+ {
+ // delegate the call to get_ptr
+ return get_ptr<PointerType>();
+ }
+
+ /*!
+ @brief get a pointer value (explicit)
+ @copydoc get()
+ */
+ template<typename PointerType, typename
+ std::enable_if<
+ std::is_pointer<PointerType>::value
+ , int>::type = 0>
+ const PointerType get() const noexcept
+ {
+ // delegate the call to get_ptr
+ return get_ptr<PointerType>();
+ }
+
+ /*!
+ @brief get a pointer value (implicit)
+
+ Implict pointer access to the internally stored JSON value. No copies are
+ made.
+
+ @warning Writing data to the pointee of the result yields an undefined
+ state.
+
+ @tparam PointerType pointer type; must be a pointer to @ref array_t, @ref
+ object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, or @ref
+ number_float_t.
+
+ @return pointer to the internally stored JSON value if the requested pointer
+ type @a PointerType fits to the JSON value; `nullptr` otherwise
+
+ @complexity Constant.
+
+ @liveexample{The example below shows how pointers to internal values of a
+ JSON value can be requested. Note that no type conversions are made and a
+ `nullptr` is returned if the value and the requested pointer type does not
+ match.,get_ptr}
+ */
+ template<typename PointerType, typename
+ std::enable_if<
+ std::is_pointer<PointerType>::value
+ , int>::type = 0>
+ PointerType get_ptr() noexcept
+ {
+ // delegate the call to get_impl_ptr<>()
+ return get_impl_ptr(static_cast<PointerType>(nullptr));
+ }
+
+ /*!
+ @brief get a pointer value (implicit)
+ @copydoc get_ptr()
+ */
+ template<typename PointerType, typename
+ std::enable_if<
+ std::is_pointer<PointerType>::value
+ and std::is_const< typename std::remove_pointer<PointerType>::type >::value
+ , int>::type = 0>
+ const PointerType get_ptr() const noexcept
+ {
+ // delegate the call to get_impl_ptr<>() const
+ return get_impl_ptr(static_cast<const PointerType>(nullptr));
+ }
+
+ /*!
+ @brief get a value (implicit)
+
+ Implict type conversion between the JSON value and a compatible value. The
+ call is realized by calling @ref get() const.
+
+ @tparam ValueType non-pointer type compatible to the JSON value, for
+ instance `int` for JSON integer numbers, `bool` for JSON booleans, or
+ `std::vector` types for JSON arrays
+
+ @return copy of the JSON value, converted to type @a ValueType
+
+ @throw std::domain_error in case passed type @a ValueType is incompatible
+ to JSON, thrown by @ref get() const
+
+ @complexity Linear in the size of the JSON value.
+
+ @liveexample{The example below shows serveral conversions from JSON values
+ to other types. There a few things to note: (1) Floating-point numbers can
+ be converted to integers\, (2) A JSON array can be converted to a standard
+ `std::vector<short>`\, (3) A JSON object can be converted to C++
+ assiciative containers such as `std::unordered_map<std::string\,
+ json>`.,operator__ValueType}
+ */
+ template<typename ValueType, typename
+ std::enable_if<
+ not std::is_pointer<ValueType>::value
+ , int>::type = 0>
+ operator ValueType() const
+ {
+ // delegate the call to get<>() const
+ return get<ValueType>();
+ }
+
+ /// @}
+
+
+ ////////////////////
+ // element access //
+ ////////////////////
+
+ /// @name element access
+ /// @{
+
+ /*!
+ @brief access specified array element with bounds checking
+
+ Returns a reference to the element at specified location @a idx, with
+ bounds checking.
+
+ @param[in] idx index of the element to access
+
+ @return reference to the element at index @a idx
+
+ @throw std::domain_error if JSON is not an array
+ @throw std::out_of_range if the index @a idx is out of range of the array;
+ that is, `idx >= size()`
+
+ @complexity Constant.
+
+ @liveexample{The example below shows how array elements can be read and
+ written using at.,at__size_type}
+ */
+ reference at(size_type idx)
+ {
+ // at only works for arrays
+ if (m_type != value_t::array)
+ {
+ throw std::domain_error("cannot use at() with " + type_name());
+ }
+
+ return m_value.array->at(idx);
+ }
+
+ /*!
+ @brief access specified array element with bounds checking
+
+ Returns a const reference to the element at specified location @a idx, with
+ bounds checking.
+
+ @param[in] idx index of the element to access
+
+ @return const reference to the element at index @a idx
+
+ @throw std::domain_error if JSON is not an array
+ @throw std::out_of_range if the index @a idx is out of range of the array;
+ that is, `idx >= size()`
+
+ @complexity Constant.
+
+ @liveexample{The example below shows how array elements can be read using
+ at.,at__size_type_const}
+ */
+ const_reference at(size_type idx) const
+ {
+ // at only works for arrays
+ if (m_type != value_t::array)
+ {
+ throw std::domain_error("cannot use at() with " + type_name());
+ }
+
+ return m_value.array->at(idx);
+ }
+
+ /*!
+ @brief access specified object element with bounds checking
+
+ Returns a reference to the element at with specified key @a key, with
+ bounds checking.
+
+ @param[in] key key of the element to access
+
+ @return reference to the element at key @a key
+
+ @throw std::domain_error if JSON is not an object
+ @throw std::out_of_range if the key @a key is is not stored in the object;
+ that is, `find(key) == end()`
+
+ @complexity Logarithmic in the size of the container.
+
+ @liveexample{The example below shows how object elements can be read and
+ written using at.,at__object_t_key_type}
+ */
+ reference at(const typename object_t::key_type& key)
+ {
+ // at only works for objects
+ if (m_type != value_t::object)
+ {
+ throw std::domain_error("cannot use at() with " + type_name());
+ }
+
+ return m_value.object->at(key);
+ }
+
+ /*!
+ @brief access specified object element with bounds checking
+
+ Returns a const reference to the element at with specified key @a key, with
+ bounds checking.
+
+ @param[in] key key of the element to access
+
+ @return const reference to the element at key @a key
+
+ @throw std::domain_error if JSON is not an object
+ @throw std::out_of_range if the key @a key is is not stored in the object;
+ that is, `find(key) == end()`
+
+ @complexity Logarithmic in the size of the container.
+
+ @liveexample{The example below shows how object elements can be read using
+ at.,at__object_t_key_type_const}
+ */
+ const_reference at(const typename object_t::key_type& key) const
+ {
+ // at only works for objects
+ if (m_type != value_t::object)
+ {
+ throw std::domain_error("cannot use at() with " + type_name());
+ }
+
+ return m_value.object->at(key);
+ }
+
+ /*!
+ @brief access specified array element
+
+ Returns a reference to the element at specified location @a idx.
+
+ @note If @a idx is beyond the range of the array (i.e., `idx >= size()`),
+ then the array is silently filled up with `null` values to make `idx` a
+ valid reference to the last stored element.
+
+ @param[in] idx index of the element to access
+
+ @return reference to the element at index @a idx
+
+ @throw std::domain_error if JSON is not an array or null
+
+ @complexity Constant if @a idx is in the range of the array. Otherwise
+ linear in `idx - size()`.
+
+ @liveexample{The example below shows how array elements can be read and
+ written using [] operator. Note the addition of `null`
+ values.,operatorarray__size_type}
+ */
+ reference operator[](size_type idx)
+ {
+ // implicitly convert null to object
+ if (m_type == value_t::null)
+ {
+ m_type = value_t::array;
+ m_value.array = create<array_t>();
+ }
+
+ // [] only works for arrays
+ if (m_type != value_t::array)
+ {
+ throw std::domain_error("cannot use operator[] with " + type_name());
+ }
+
+ for (size_t i = m_value.array->size(); i <= idx; ++i)
+ {
+ m_value.array->push_back(basic_json());
+ }
+
+ return m_value.array->operator[](idx);
+ }
+
+ /*!
+ @brief access specified array element
+
+ Returns a const reference to the element at specified location @a idx.
+
+ @param[in] idx index of the element to access
+
+ @return const reference to the element at index @a idx
+
+ @throw std::domain_error if JSON is not an array
+
+ @complexity Constant.
+
+ @liveexample{The example below shows how array elements can be read using
+ the [] operator.,operatorarray__size_type_const}
+ */
+ const_reference operator[](size_type idx) const
+ {
+ // at only works for arrays
+ if (m_type != value_t::array)
+ {
+ throw std::domain_error("cannot use operator[] with " + type_name());
+ }
+
+ return m_value.array->operator[](idx);
+ }
+
+ /*!
+ @brief access specified object element
+
+ Returns a reference to the element at with specified key @a key.
+
+ @note If @a key is not found in the object, then it is silently added to
+ the object and filled with a `null` value to make `key` a valid reference.
+ In case the value was `null` before, it is converted to an object.
+
+ @param[in] key key of the element to access
+
+ @return reference to the element at key @a key
+
+ @throw std::domain_error if JSON is not an object or null
+
+ @complexity Logarithmic in the size of the container.
+
+ @liveexample{The example below shows how object elements can be read and
+ written using the [] operator.,operatorarray__key_type}
+ */
+ reference operator[](const typename object_t::key_type& key)
+ {
+ // implicitly convert null to object
+ if (m_type == value_t::null)
+ {
+ m_type = value_t::object;
+ m_value.object = create<object_t>();
+ }
+
+ // [] only works for objects
+ if (m_type != value_t::object)
+ {
+ throw std::domain_error("cannot use operator[] with " + type_name());
+ }
+
+ return m_value.object->operator[](key);
+ }
+
+ /*!
+ @brief access specified object element
+
+ Returns a reference to the element at with specified key @a key.
+
+ @param[in] key key of the element to access
+
+ @return reference to the element at key @a key
+
+ @throw std::domain_error if JSON is not an object or null
+
+ @complexity Logarithmic in the size of the container.
+
+ @liveexample{The example below shows how object elements can be read using
+ the [] operator.,operatorarray__key_type_const}
+ */
+ const_reference operator[](const typename object_t::key_type& key) const
+ {
+ // at only works for objects
+ if (m_type != value_t::object)
+ {
+ throw std::domain_error("cannot use operator[] with " + type_name());
+ }
+
+ return m_value.object->operator[](key);
+ }
+
+ /*!
+ @brief access specified object element
+
+ Returns a reference to the element at with specified key @a key.
+
+ @note If @a key is not found in the object, then it is silently added to
+ the object and filled with a `null` value to make `key` a valid reference.
+ In case the value was `null` before, it is converted to an object.
+
+ @note This function is required for compatibility reasons with Clang.
+
+ @param[in] key key of the element to access
+
+ @return reference to the element at key @a key
+
+ @throw std::domain_error if JSON is not an object or null
+
+ @complexity Logarithmic in the size of the container.
+
+ @liveexample{The example below shows how object elements can be read and
+ written using the [] operator.,operatorarray__key_type}
+ */
+ template<typename T, std::size_t n>
+ reference operator[](const T (&key)[n])
+ {
+ // implicitly convert null to object
+ if (m_type == value_t::null)
+ {
+ m_type = value_t::object;
+ m_value = value_t::object;
+ }
+
+ // at only works for objects
+ if (m_type != value_t::object)
+ {
+ throw std::domain_error("cannot use operator[] with " + type_name());
+ }
+
+ return m_value.object->operator[](key);
+ }
+
+ /*!
+ @brief access specified object element
+
+ Returns a reference to the element at with specified key @a key.
+
+ @note This function is required for compatibility reasons with Clang.
+
+ @param[in] key key of the element to access
+
+ @return reference to the element at key @a key
+
+ @throw std::domain_error if JSON is not an object or null
+
+ @complexity Logarithmic in the size of the container.
+
+ @liveexample{The example below shows how object elements can be read using
+ the [] operator.,operatorarray__key_type_const}
+ */
+ template<typename T, std::size_t n>
+ const_reference operator[](const T (&key)[n]) const
+ {
+ // at only works for objects
+ if (m_type != value_t::object)
+ {
+ throw std::domain_error("cannot use operator[] with " + type_name());
+ }
+
+ return m_value.object->operator[](key);
+ }
+
+ /*!
+ @brief access the first element
+
+ Returns a reference to the first element in the container. For a JSON
+ container `c`, the expression `c.front()` is equivalent to `*c.begin()`.
+
+ @return In case of a structured type (array or object), a reference to the
+ first element is returned. In cast of number, string, or boolean values, a
+ reference to the value is returned.
+
+ @complexity Constant.
+
+ @note Calling `front` on an empty container is undefined.
+
+ @throw std::out_of_range when called on null value
+
+ @liveexample{The following code shows an example for @ref front.,front}
+ */
+ reference front()
+ {
+ return *begin();
+ }
+
+ /*!
+ @copydoc basic_json::front()
+ */
+ const_reference front() const
+ {
+ return *cbegin();
+ }
+
+ /*!
+ @brief access the last element
+
+ Returns a reference to the last element in the container. For a JSON
+ container `c`, the expression `c.back()` is equivalent to `{ auto tmp =
+ c.end(); --tmp; return *tmp; }`.
+
+ @return In case of a structured type (array or object), a reference to the
+ last element is returned. In cast of number, string, or boolean values, a
+ reference to the value is returned.
+
+ @complexity Constant.
+
+ @note Calling `back` on an empty container is undefined.
+
+ @throw std::out_of_range when called on null value.
+
+ @liveexample{The following code shows an example for @ref back.,back}
+ */
+ reference back()
+ {
+ auto tmp = end();
+ --tmp;
+ return *tmp;
+ }
+
+ /*!
+ @copydoc basic_json::back()
+ */
+ const_reference back() const
+ {
+ auto tmp = cend();
+ --tmp;
+ return *tmp;
+ }
+
+ /*!
+ @brief remove element given an iterator
+
+ Removes the element specified by iterator @a pos. Invalidates iterators and
+ references at or after the point of the erase, including the end()
+ iterator. The iterator @a pos must be valid and dereferenceable. Thus the
+ end() iterator (which is valid, but is not dereferencable) cannot be used
+ as a value for @a pos.
+
+ If called on a primitive type other than null, the resulting JSON value
+ will be `null`.
+
+ @param[in] pos iterator to the element to remove
+ @return Iterator following the last removed element. If the iterator @a pos
+ refers to the last element, the end() iterator is returned.
+
+ @tparam InteratorType an @ref iterator or @ref const_iterator
+
+ @throw std::domain_error if called on a `null` value
+ @throw std::domain_error if called on an iterator which does not belong to
+ the current JSON value
+ @throw std::out_of_range if called on a primitive type with invalid iterator
+ (i.e., any iterator which is not end())
+
+ @complexity The complexity depends on the type:
+ - objects: amortized constant
+ - arrays: linear in distance between pos and the end of the container
+ - strings: linear in the length of the string
+ - other types: constant
+
+ @liveexample{The example shows the result of erase for different JSON
+ types.,erase__IteratorType}
+ */
+ template <class InteratorType, typename
+ std::enable_if<
+ std::is_same<InteratorType, typename basic_json_t::iterator>::value or
+ std::is_same<InteratorType, typename basic_json_t::const_iterator>::value
+ , int>::type
+ = 0>
+ InteratorType erase(InteratorType pos)
+ {
+ // make sure iterator fits the current value
+ if (this != pos.m_object)
+ {
+ throw std::domain_error("iterator does not fit current value");
+ }
+
+ InteratorType result = end();
+
+ switch (m_type)
+ {
+ case value_t::number_integer:
+ case value_t::number_float:
+ case value_t::boolean:
+ case value_t::string:
+ {
+ if (not pos.m_it.primitive_iterator.is_begin())
+ {
+ throw std::out_of_range("iterator out of range");
+ }
+
+ if (m_type == value_t::string)
+ {
+ delete m_value.string;
+ m_value.string = nullptr;
+ }
+
+ m_type = value_t::null;
+ break;
+ }
+
+ case value_t::object:
+ {
+ result.m_it.object_iterator = m_value.object->erase(pos.m_it.object_iterator);
+ break;
+ }
+
+ case value_t::array:
+ {
+ result.m_it.array_iterator = m_value.array->erase(pos.m_it.array_iterator);
+ break;
+ }
+
+ default:
+ {
+ throw std::domain_error("cannot use erase() with " + type_name());
+ }
+ }
+
+ return result;
+ }
+
+ /*!
+ @brief remove elements given an iterator range
+
+ Removes the element specified by the range `[first; last)`. Invalidates
+ iterators and references at or after the point of the erase, including the
+ end() iterator. The iterator @a first does not need to be dereferenceable
+ if `first == last`: erasing an empty range is a no-op.
+
+ If called on a primitive type other than null, the resulting JSON value
+ will be `null`.
+
+ @param[in] first iterator to the beginning of the range to remove
+ @param[in] last iterator past the end of the range to remove
+ @return Iterator following the last removed element. If the iterator @a
+ second refers to the last element, the end() iterator is returned.
+
+ @tparam InteratorType an @ref iterator or @ref const_iterator
+
+ @throw std::domain_error if called on a `null` value
+ @throw std::domain_error if called on iterators which does not belong to
+ the current JSON value
+ @throw std::out_of_range if called on a primitive type with invalid iterators
+ (i.e., if `first != begin()` and `last != end()`)
+
+ @complexity The complexity depends on the type:
+ - objects: `log(size()) + std::distance(first, last)`
+ - arrays: linear in the distance between @a first and @a last, plus linear
+ in the distance between @a last and end of the container
+ - strings: linear in the length of the string
+ - other types: constant
+
+ @liveexample{The example shows the result of erase for different JSON
+ types.,erase__IteratorType_IteratorType}
+ */
+ template <class InteratorType, typename
+ std::enable_if<
+ std::is_same<InteratorType, typename basic_json_t::iterator>::value or
+ std::is_same<InteratorType, typename basic_json_t::const_iterator>::value
+ , int>::type
+ = 0>
+ InteratorType erase(InteratorType first, InteratorType last)
+ {
+ // make sure iterator fits the current value
+ if (this != first.m_object or this != last.m_object)
+ {
+ throw std::domain_error("iterators do not fit current value");
+ }
+
+ InteratorType result = end();
+
+ switch (m_type)
+ {
+ case value_t::number_integer:
+ case value_t::number_float:
+ case value_t::boolean:
+ case value_t::string:
+ {
+ if (not first.m_it.primitive_iterator.is_begin() or not last.m_it.primitive_iterator.is_end())
+ {
+ throw std::out_of_range("iterators out of range");
+ }
+
+ if (m_type == value_t::string)
+ {
+ delete m_value.string;
+ m_value.string = nullptr;
+ }
+
+ m_type = value_t::null;
+ break;
+ }
+
+ case value_t::object:
+ {
+ result.m_it.object_iterator = m_value.object->erase(first.m_it.object_iterator,
+ last.m_it.object_iterator);
+ break;
+ }
+
+ case value_t::array:
+ {
+ result.m_it.array_iterator = m_value.array->erase(first.m_it.array_iterator,
+ last.m_it.array_iterator);
+ break;
+ }
+
+ default:
+ {
+ throw std::domain_error("cannot use erase with " + type_name());
+ }
+ }
+
+ return result;
+ }
+
+ /*!
+ @brief remove element from a JSON object given a key
+
+ Removes elements from a JSON object with the key value @a key.
+
+ @param[in] key value of the elements to remove
+
+ @return Number of elements removed. If ObjectType is the default `std::map`
+ type, the return value will always be `0` (@a key was not found) or `1` (@a
+ key was found).
+
+ @throw std::domain_error when called on a type other than JSON object
+
+ @complexity `log(size()) + count(key)`
+
+ @liveexample{The example shows the effect of erase.,erase__key_type}
+ */
+ size_type erase(const typename object_t::key_type& key)
+ {
+ // this erase only works for objects
+ if (m_type != value_t::object)
+ {
+ throw std::domain_error("cannot use erase() with " + type_name());
+ }
+
+ return m_value.object->erase(key);
+ }
+
+ /*!
+ @brief remove element from a JSON array given an index
+
+ Removes element from a JSON array at the index @a idx.
+
+ @param[in] idx index of the element to remove
+
+ @throw std::domain_error when called on a type other than JSON array
+ @throw std::out_of_range when `idx >= size()`
+
+ @complexity Linear in distance between @a idx and the end of the container.
+
+ @liveexample{The example shows the effect of erase.,erase__size_type}
+ */
+ void erase(const size_type idx)
+ {
+ // this erase only works for arrays
+ if (m_type != value_t::array)
+ {
+ throw std::domain_error("cannot use erase() with " + type_name());
+ }
+
+ if (idx >= size())
+ {
+ throw std::out_of_range("index out of range");
+ }
+
+ m_value.array->erase(m_value.array->begin() + static_cast<difference_type>(idx));
+ }
+
+ /*!
+ @brief find an element in a JSON object
+
+ Finds an element in a JSON object with key equivalent to @a key. If the
+ element is not found or the JSON value is not an object, end() is returned.
+
+ @param[in] key key value of the element to search for
+
+ @return Iterator to an element with key equivalent to @a key. If no such
+ element is found, past-the-end (see end()) iterator is returned.
+
+ @complexity Logarithmic in the size of the JSON object.
+
+ @liveexample{The example shows how find is used.,find__key_type}
+ */
+ iterator find(typename object_t::key_type key)
+ {
+ auto result = end();
+
+ if (m_type == value_t::object)
+ {
+ result.m_it.object_iterator = m_value.object->find(key);
+ }
+
+ return result;
+ }
+
+ /*!
+ @brief find an element in a JSON object
+ @copydoc find(typename object_t::key_type)
+ */
+ const_iterator find(typename object_t::key_type key) const
+ {
+ auto result = cend();
+
+ if (m_type == value_t::object)
+ {
+ result.m_it.object_iterator = m_value.object->find(key);
+ }
+
+ return result;
+ }
+
+ /*!
+ @brief returns the number of occurrences of a key in a JSON object
+
+ Returns the number of elements with key @a key. If ObjectType is the
+ default `std::map` type, the return value will always be `0` (@a key was
+ not found) or `1` (@a key was found).
+
+ @param[in] key key value of the element to count
+
+ @return Number of elements with key @a key. If the JSON value is not an
+ object, the return value will be `0`.
+
+ @complexity Logarithmic in the size of the JSON object.
+
+ @liveexample{The example shows how count is used.,count}
+ */
+ size_type count(typename object_t::key_type key) const
+ {
+ // return 0 for all nonobject types
+ return (m_type == value_t::object) ? m_value.object->count(key) : 0;
+ }
+
+ /// @}
+
+
+ ///////////////
+ // iterators //
+ ///////////////
+
+ /// @name iterators
+ /// @{
+
+ /*!
+ @brief returns an iterator to the first element
+
+ Returns an iterator to the first element.
+
+ @image html range-begin-end.svg "Illustration from cppreference.com"
+
+ @return iterator to the first element
+
+ @complexity Constant.
+
+ @requirement This function satisfies the Container requirements:
+ - The complexity is constant.
+
+ @liveexample{The following code shows an example for @ref begin.,begin}
+ */
+ iterator begin()
+ {
+ iterator result(this);
+ result.set_begin();
+ return result;
+ }
+
+ /*!
+ @copydoc basic_json::cbegin()
+ */
+ const_iterator begin() const
+ {
+ return cbegin();
+ }
+
+ /*!
+ @brief returns a const iterator to the first element
+
+ Returns a const iterator to the first element.
+
+ @image html range-begin-end.svg "Illustration from cppreference.com"
+
+ @return const iterator to the first element
+
+ @complexity Constant.
+
+ @requirement This function satisfies the Container requirements:
+ - The complexity is constant.
+ - Has the semantics of `const_cast<const basic_json&>(*this).begin()`.
+
+ @liveexample{The following code shows an example for @ref cbegin.,cbegin}
+ */
+ const_iterator cbegin() const
+ {
+ const_iterator result(this);
+ result.set_begin();
+ return result;
+ }
+
+ /*!
+ @brief returns an iterator to one past the last element
+
+ Returns an iterator to one past the last element.
+
+ @image html range-begin-end.svg "Illustration from cppreference.com"
+
+ @return iterator one past the last element
+
+ @complexity Constant.
+
+ @requirement This function satisfies the Container requirements:
+ - The complexity is constant.
+
+ @liveexample{The following code shows an example for @ref end.,end}
+ */
+ iterator end()
+ {
+ iterator result(this);
+ result.set_end();
+ return result;
+ }
+
+ /*!
+ @copydoc basic_json::cend()
+ */
+ const_iterator end() const
+ {
+ return cend();
+ }
+
+ /*!
+ @brief returns a const iterator to one past the last element
+
+ Returns a const iterator to one past the last element.
+
+ @image html range-begin-end.svg "Illustration from cppreference.com"
+
+ @return const iterator one past the last element
+
+ @complexity Constant.
+
+ @requirement This function satisfies the Container requirements:
+ - The complexity is constant.
+ - Has the semantics of `const_cast<const basic_json&>(*this).end()`.
+
+ @liveexample{The following code shows an example for @ref cend.,cend}
+ */
+ const_iterator cend() const
+ {
+ const_iterator result(this);
+ result.set_end();
+ return result;
+ }
+
+ /*!
+ @brief returns an iterator to the reverse-beginning
+
+ Returns an iterator to the reverse-beginning; that is, the last element.
+
+ @image html range-rbegin-rend.svg "Illustration from cppreference.com"
+
+ @complexity Constant.
+
+ @requirement This function satisfies the ReversibleContainer requirements:
+ - The complexity is constant.
+ - Has the semantics of `reverse_iterator(end())`.
+
+ @liveexample{The following code shows an example for @ref rbegin.,rbegin}
+ */
+ reverse_iterator rbegin()
+ {
+ return reverse_iterator(end());
+ }
+
+ /*!
+ @copydoc basic_json::crbegin()
+ */
+ const_reverse_iterator rbegin() const
+ {
+ return crbegin();
+ }
+
+ /*!
+ @brief returns an iterator to the reverse-end
+
+ Returns an iterator to the reverse-end; that is, one before the first
+ element.
+
+ @image html range-rbegin-rend.svg "Illustration from cppreference.com"
+
+ @complexity Constant.
+
+ @requirement This function satisfies the ReversibleContainer requirements:
+ - The complexity is constant.
+ - Has the semantics of `reverse_iterator(begin())`.
+
+ @liveexample{The following code shows an example for @ref rend.,rend}
+ */
+ reverse_iterator rend()
+ {
+ return reverse_iterator(begin());
+ }
+
+ /*!
+ @copydoc basic_json::crend()
+ */
+ const_reverse_iterator rend() const
+ {
+ return crend();
+ }
+
+ /*!
+ @brief returns a const reverse iterator to the last element
+
+ Returns a const iterator to the reverse-beginning; that is, the last
+ element.
+
+ @image html range-rbegin-rend.svg "Illustration from cppreference.com"
+
+ @complexity Constant.
+
+ @requirement This function satisfies the ReversibleContainer requirements:
+ - The complexity is constant.
+ - Has the semantics of `const_cast<const basic_json&>(*this).rbegin()`.
+
+ @liveexample{The following code shows an example for @ref crbegin.,crbegin}
+ */
+ const_reverse_iterator crbegin() const
+ {
+ return const_reverse_iterator(cend());
+ }
+
+ /*!
+ @brief returns a const reverse iterator to one before the first
+
+ Returns a const reverse iterator to the reverse-end; that is, one before
+ the first element.
+
+ @image html range-rbegin-rend.svg "Illustration from cppreference.com"
+
+ @complexity Constant.
+
+ @requirement This function satisfies the ReversibleContainer requirements:
+ - The complexity is constant.
+ - Has the semantics of `const_cast<const basic_json&>(*this).rend()`.
+
+ @liveexample{The following code shows an example for @ref crend.,crend}
+ */
+ const_reverse_iterator crend() const
+ {
+ return const_reverse_iterator(cbegin());
+ }
+
+ /// @}
+
+
+ //////////////
+ // capacity //
+ //////////////
+
+ /// @name capacity
+ /// @{
+
+ /*!
+ @brief checks whether the container is empty
+
+ Checks if a JSON value has no elements.
+
+ @return The return value depends on the different types and is
+ defined as follows:
+ Value type | return value
+ ----------- | -------------
+ null | @c true
+ boolean | @c false
+ string | @c false
+ number | @c false
+ object | result of function object_t::empty()
+ array | result of function array_t::empty()
+
+ @complexity Constant, as long as @ref array_t and @ref object_t satisfy the
+ Container concept; that is, their empty() functions have
+ constant complexity.
+
+ @requirement This function satisfies the Container requirements:
+ - The complexity is constant.
+ - Has the semantics of `begin() == end()`.
+
+ @liveexample{The following code uses @ref empty to check if a @ref json
+ object contains any elements.,empty}
+ */
+ bool empty() const noexcept
+ {
+ switch (m_type)
+ {
+ case (value_t::null):
+ {
+ return true;
+ }
+
+ case (value_t::array):
+ {
+ return m_value.array->empty();
+ }
+
+ case (value_t::object):
+ {
+ return m_value.object->empty();
+ }
+
+ default:
+ {
+ // all other types are nonempty
+ return false;
+ }
+ }
+ }
+
+ /*!
+ @brief returns the number of elements
+
+ Returns the number of elements in a JSON value.
+
+ @return The return value depends on the different types and is
+ defined as follows:
+ Value type | return value
+ ----------- | -------------
+ null | @c 0
+ boolean | @c 1
+ string | @c 1
+ number | @c 1
+ object | result of function object_t::size()
+ array | result of function array_t::size()
+
+ @complexity Constant, as long as @ref array_t and @ref object_t satisfy the
+ Container concept; that is, their size() functions have
+ constant complexity.
+
+ @requirement This function satisfies the Container requirements:
+ - The complexity is constant.
+ - Has the semantics of `std::distance(begin(), end())`.
+
+ @liveexample{The following code calls @ref size on the different value
+ types.,size}
+ */
+ size_type size() const noexcept
+ {
+ switch (m_type)
+ {
+ case (value_t::null):
+ {
+ return 0;
+ }
+
+ case (value_t::array):
+ {
+ return m_value.array->size();
+ }
+
+ case (value_t::object):
+ {
+ return m_value.object->size();
+ }
+
+ default:
+ {
+ // all other types have size 1
+ return 1;
+ }
+ }
+ }
+
+ /*!
+ @brief returns the maximum possible number of elements
+
+ Returns the maximum number of elements a JSON value is able to hold due to
+ system or library implementation limitations, i.e. `std::distance(begin(),
+ end())` for the JSON value.
+
+ @return The return value depends on the different types and is
+ defined as follows:
+ Value type | return value
+ ----------- | -------------
+ null | @c 0 (same as size())
+ boolean | @c 1 (same as size())
+ string | @c 1 (same as size())
+ number | @c 1 (same as size())
+ object | result of function object_t::max_size()
+ array | result of function array_t::max_size()
+
+ @complexity Constant, as long as @ref array_t and @ref object_t satisfy the
+ Container concept; that is, their max_size() functions have
+ constant complexity.
+
+ @requirement This function satisfies the Container requirements:
+ - The complexity is constant.
+ - Has the semantics of returning `b.size()` where `b` is the largest
+ possible JSON value.
+
+ @liveexample{The following code calls @ref max_size on the different value
+ types. Note the output is implementation specific.,max_size}
+ */
+ size_type max_size() const noexcept
+ {
+ switch (m_type)
+ {
+ case (value_t::array):
+ {
+ return m_value.array->max_size();
+ }
+
+ case (value_t::object):
+ {
+ return m_value.object->max_size();
+ }
+
+ default:
+ {
+ // all other types have max_size() == size()
+ return size();
+ }
+ }
+ }
+
+ /// @}
+
+
+ ///////////////
+ // modifiers //
+ ///////////////
+
+ /// @name modifiers
+ /// @{
+
+ /*!
+ @brief clears the contents
+
+ Clears the content of a JSON value and resets it to the default value as
+ if @ref basic_json(value_t) would have been called:
+
+ Value type | initial value
+ ----------- | -------------
+ null | `null`
+ boolean | `false`
+ string | `""`
+ number | `0`
+ object | `{}`
+ array | `[]`
+
+ @note Floating-point numbers are set to `0.0` which will be serialized to
+ `0`. The vale type remains @ref number_float_t.
+
+ @complexity Linear in the size of the JSON value.
+
+ @liveexample{The example below shows the effect of @ref clear to different
+ JSON types.,clear}
+ */
+ void clear() noexcept
+ {
+ switch (m_type)
+ {
+ case (value_t::null):
+ case (value_t::discarded):
+ {
+ break;
+ }
+
+ case (value_t::number_integer):
+ {
+ m_value.number_integer = 0;
+ break;
+ }
+
+ case (value_t::number_float):
+ {
+ m_value.number_float = 0.0;
+ break;
+ }
+
+ case (value_t::boolean):
+ {
+ m_value.boolean = false;
+ break;
+ }
+
+ case (value_t::string):
+ {
+ m_value.string->clear();
+ break;
+ }
+
+ case (value_t::array):
+ {
+ m_value.array->clear();
+ break;
+ }
+
+ case (value_t::object):
+ {
+ m_value.object->clear();
+ break;
+ }
+ }
+ }
+
+ /*!
+ @brief add an object to an array
+
+ Appends the given element @a value to the end of the JSON value. If the
+ function is called on a JSON null value, an empty array is created before
+ appending @a value.
+
+ @param value the value to add to the JSON array
+
+ @throw std::domain_error when called on a type other than JSON array or null
+
+ @complexity Amortized constant.
+
+ @liveexample{The example shows how `push_back` and `+=` can be used to add
+ elements to a JSON array. Note how the `null` value was silently converted
+ to a JSON array.,push_back}
+ */
+ void push_back(basic_json&& value)
+ {
+ // push_back only works for null objects or arrays
+ if (not(m_type == value_t::null or m_type == value_t::array))
+ {
+ throw std::domain_error("cannot use push_back() with " + type_name());
+ }
+
+ // transform null object into an array
+ if (m_type == value_t::null)
+ {
+ m_type = value_t::array;
+ m_value = value_t::array;
+ }
+
+ // add element to array (move semantics)
+ m_value.array->push_back(std::move(value));
+ // invalidate object
+ value.m_type = value_t::null;
+ }
+
+ /*!
+ @brief add an object to an array
+ @copydoc push_back(basic_json&&)
+ */
+ reference operator+=(basic_json&& value)
+ {
+ push_back(std::move(value));
+ return *this;
+ }
+
+ /*!
+ @brief add an object to an array
+ @copydoc push_back(basic_json&&)
+ */
+ void push_back(const basic_json& value)
+ {
+ // push_back only works for null objects or arrays
+ if (not(m_type == value_t::null or m_type == value_t::array))
+ {
+ throw std::domain_error("cannot use push_back() with " + type_name());
+ }
+
+ // transform null object into an array
+ if (m_type == value_t::null)
+ {
+ m_type = value_t::array;
+ m_value = value_t::array;
+ }
+
+ // add element to array
+ m_value.array->push_back(value);
+ }
+
+ /*!
+ @brief add an object to an array
+ @copydoc push_back(basic_json&&)
+ */
+ reference operator+=(const basic_json& value)
+ {
+ push_back(value);
+ return *this;
+ }
+
+ /*!
+ @brief add an object to an object
+
+ Inserts the given element @a value to the JSON object. If the function is
+ called on a JSON null value, an empty object is created before inserting @a
+ value.
+
+ @param[in] value the value to add to the JSON object
+
+ @throw std::domain_error when called on a type other than JSON object or
+ null
+
+ @complexity Logarithmic in the size of the container, O(log(`size()`)).
+
+ @liveexample{The example shows how `push_back` and `+=` can be used to add
+ elements to a JSON object. Note how the `null` value was silently converted
+ to a JSON object.,push_back__object_t__value}
+ */
+ void push_back(const typename object_t::value_type& value)
+ {
+ // push_back only works for null objects or objects
+ if (not(m_type == value_t::null or m_type == value_t::object))
+ {
+ throw std::domain_error("cannot use push_back() with " + type_name());
+ }
+
+ // transform null object into an object
+ if (m_type == value_t::null)
+ {
+ m_type = value_t::object;
+ m_value = value_t::object;
+ }
+
+ // add element to array
+ m_value.object->insert(value);
+ }
+
+ /*!
+ @brief add an object to an object
+ @copydoc push_back(const typename object_t::value_type&)
+ */
+ reference operator+=(const typename object_t::value_type& value)
+ {
+ push_back(value);
+ return operator[](value.first);
+ }
+
+ /*!
+ @brief inserts element
+
+ Inserts element @a value before iterator @a pos.
+
+ @param[in] pos iterator before which the content will be inserted; may be
+ the end() iterator
+ @param[in] value element to insert
+ @return iterator pointing to the inserted @a value.
+
+ @throw std::domain_error if called on JSON values other than arrays
+ @throw std::domain_error if @a pos is not an iterator of *this
+
+ @complexity Constant plus linear in the distance between pos and end of the
+ container.
+
+ @liveexample{The example shows how insert is used.,insert}
+ */
+ iterator insert(const_iterator pos, const basic_json& value)
+ {
+ // insert only works for arrays
+ if (m_type != value_t::array)
+ {
+ throw std::domain_error("cannot use insert() with " + type_name());
+ }
+
+ // check if iterator pos fits to this JSON value
+ if (pos.m_object != this)
+ {
+ throw std::domain_error("iterator does not fit current value");
+ }
+
+ // insert to array and return iterator
+ iterator result(this);
+ result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, value);
+ return result;
+ }
+
+ /*!
+ @brief inserts element
+ @copydoc insert(const_iterator, const basic_json&)
+ */
+ iterator insert(const_iterator pos, basic_json&& value)
+ {
+ return insert(pos, value);
+ }
+
+ /*!
+ @brief inserts elements
+
+ Inserts @a count copies of @a value before iterator @a pos.
+
+ @param[in] pos iterator before which the content will be inserted; may be
+ the end() iterator
+ @param[in] count number of copies of @a value to insert
+ @param[in] value element to insert
+ @return iterator pointing to the first element inserted, or @a pos if
+ `count==0`
+
+ @throw std::domain_error if called on JSON values other than arrays
+ @throw std::domain_error if @a pos is not an iterator of *this
+
+ @complexity Linear in @a count plus linear in the distance between @a pos
+ and end of the container.
+
+ @liveexample{The example shows how insert is used.,insert__count}
+ */
+ iterator insert(const_iterator pos, size_type count, const basic_json& value)
+ {
+ // insert only works for arrays
+ if (m_type != value_t::array)
+ {
+ throw std::domain_error("cannot use insert() with " + type_name());
+ }
+
+ // check if iterator pos fits to this JSON value
+ if (pos.m_object != this)
+ {
+ throw std::domain_error("iterator does not fit current value");
+ }
+
+ // insert to array and return iterator
+ iterator result(this);
+ result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, count, value);
+ return result;
+ }
+
+ /*!
+ @brief inserts elements
+
+ Inserts elements from range `[first, last)` before iterator @a pos.
+
+ @param[in] pos iterator before which the content will be inserted; may be
+ the end() iterator
+ @param[in] first begin of the range of elements to insert
+ @param[in] last end of the range of elements to insert
+
+ @throw std::domain_error if called on JSON values other than arrays
+ @throw std::domain_error if @a pos is not an iterator of *this
+ @throw std::domain_error if @a first and @a last do not belong to the same
+ JSON value
+ @throw std::domain_error if @a first or @a last are iterators into
+ container for which insert is called
+ @return iterator pointing to the first element inserted, or @a pos if
+ `first==last`
+
+ @complexity Linear in `std::distance(first, last)` plus linear in the
+ distance between @a pos and end of the container.
+
+ @liveexample{The example shows how insert is used.,insert__range}
+ */
+ iterator insert(const_iterator pos, const_iterator first, const_iterator last)
+ {
+ // insert only works for arrays
+ if (m_type != value_t::array)
+ {
+ throw std::domain_error("cannot use insert() with " + type_name());
+ }
+
+ // check if iterator pos fits to this JSON value
+ if (pos.m_object != this)
+ {
+ throw std::domain_error("iterator does not fit current value");
+ }
+
+ if (first.m_object != last.m_object)
+ {
+ throw std::domain_error("iterators does not fit");
+ }
+
+ if (first.m_object == this or last.m_object == this)
+ {
+ throw std::domain_error("passed iterators may not belong to container");
+ }
+
+ // insert to array and return iterator
+ iterator result(this);
+ result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator,
+ first.m_it.array_iterator, last.m_it.array_iterator);
+ return result;
+ }
+
+ /*!
+ @brief inserts elements
+
+ Inserts elements from initializer list @a ilist before iterator @a pos.
+
+ @param[in] pos iterator before which the content will be inserted; may be
+ the end() iterator
+ @param[in] ilist initializer list to insert the values from
+
+ @throw std::domain_error if called on JSON values other than arrays
+ @throw std::domain_error if @a pos is not an iterator of *this
+ @return iterator pointing to the first element inserted, or @a pos if
+ `ilist` is empty
+
+ @complexity Linear in `ilist.size()` plus linear in the distance between @a
+ pos and end of the container.
+
+ @liveexample{The example shows how insert is used.,insert__ilist}
+ */
+ iterator insert(const_iterator pos, std::initializer_list<basic_json> ilist)
+ {
+ // insert only works for arrays
+ if (m_type != value_t::array)
+ {
+ throw std::domain_error("cannot use insert() with " + type_name());
+ }
+
+ // check if iterator pos fits to this JSON value
+ if (pos.m_object != this)
+ {
+ throw std::domain_error("iterator does not fit current value");
+ }
+
+ // insert to array and return iterator
+ iterator result(this);
+ result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, ilist);
+ return result;
+ }
+
+ /*!
+ @brief exchanges the values
+
+ Exchanges the contents of the JSON value with those of @a other. Does not
+ invoke any move, copy, or swap operations on individual elements. All
+ iterators and references remain valid. The past-the-end iterator is
+ invalidated.
+
+ @param[in,out] other JSON value to exchange the contents with
+
+ @complexity Constant.
+
+ @liveexample{The example below shows how JSON arrays can be
+ swapped.,swap__reference}
+ */
+ void swap(reference other) noexcept (
+ std::is_nothrow_move_constructible<value_t>::value and
+ std::is_nothrow_move_assignable<value_t>::value and
+ std::is_nothrow_move_constructible<json_value>::value and
+ std::is_nothrow_move_assignable<json_value>::value
+ )
+ {
+ std::swap(m_type, other.m_type);
+ std::swap(m_value, other.m_value);
+ }
+
+ /*!
+ @brief exchanges the values
+
+ Exchanges the contents of a JSON array with those of @a other. Does not
+ invoke any move, copy, or swap operations on individual elements. All
+ iterators and references remain valid. The past-the-end iterator is
+ invalidated.
+
+ @param[in,out] other array to exchange the contents with
+
+ @throw std::domain_error when JSON value is not an array
+
+ @complexity Constant.
+
+ @liveexample{The example below shows how JSON values can be
+ swapped.,swap__array_t}
+ */
+ void swap(array_t& other)
+ {
+ // swap only works for arrays
+ if (m_type != value_t::array)
+ {
+ throw std::domain_error("cannot use swap() with " + type_name());
+ }
+
+ // swap arrays
+ std::swap(*(m_value.array), other);
+ }
+
+ /*!
+ @brief exchanges the values
+
+ Exchanges the contents of a JSON object with those of @a other. Does not
+ invoke any move, copy, or swap operations on individual elements. All
+ iterators and references remain valid. The past-the-end iterator is
+ invalidated.
+
+ @param[in,out] other object to exchange the contents with
+
+ @throw std::domain_error when JSON value is not an object
+
+ @complexity Constant.
+
+ @liveexample{The example below shows how JSON values can be
+ swapped.,swap__object_t}
+ */
+ void swap(object_t& other)
+ {
+ // swap only works for objects
+ if (m_type != value_t::object)
+ {
+ throw std::domain_error("cannot use swap() with " + type_name());
+ }
+
+ // swap objects
+ std::swap(*(m_value.object), other);
+ }
+
+ /*!
+ @brief exchanges the values
+
+ Exchanges the contents of a JSON string with those of @a other. Does not
+ invoke any move, copy, or swap operations on individual elements. All
+ iterators and references remain valid. The past-the-end iterator is
+ invalidated.
+
+ @param[in,out] other string to exchange the contents with
+
+ @throw std::domain_error when JSON value is not a string
+
+ @complexity Constant.
+
+ @liveexample{The example below shows how JSON values can be
+ swapped.,swap__string_t}
+ */
+ void swap(string_t& other)
+ {
+ // swap only works for strings
+ if (m_type != value_t::string)
+ {
+ throw std::domain_error("cannot use swap() with " + type_name());
+ }
+
+ // swap strings
+ std::swap(*(m_value.string), other);
+ }
+
+ /// @}
+
+
+ //////////////////////////////////////////
+ // lexicographical comparison operators //
+ //////////////////////////////////////////
+
+ /// @name lexicographical comparison operators
+ /// @{
+
+ private:
+ /*!
+ @brief comparison operator for JSON types
+
+ Returns an ordering that is similar to Python:
+ - order: null < boolean < number < object < array < string
+ - furthermore, each type is not smaller than itself
+ */
+ friend bool operator<(const value_t lhs, const value_t rhs)
+ {
+ static constexpr std::array<uint8_t, 7> order = {{
+ 0, // null
+ 3, // object
+ 4, // array
+ 5, // string
+ 1, // boolean
+ 2, // integer
+ 2 // float
+ }
+ };
+
+ // discarded values are not comparable
+ if (lhs == value_t::discarded or rhs == value_t::discarded)
+ {
+ return false;
+ }
+
+ return order[static_cast<std::size_t>(lhs)] < order[static_cast<std::size_t>(rhs)];
+ }
+
+ public:
+ /*!
+ @brief comparison: equal
+
+ Compares two JSON values for equality according to the following rules:
+ - Two JSON values are equal if (1) they are from the same type and (2)
+ their stored values are the same.
+ - Integer and floating-point numbers are automatically converted before
+ comparison. Floating-point numbers are compared indirectly: two
+ floating-point numbers `f1` and `f2` are considered equal if neither
+ `f1 > f2` nor `f2 > f1` holds.
+ - Two JSON null values are equal.
+
+ @param[in] lhs first JSON value to consider
+ @param[in] rhs second JSON value to consider
+ @return whether the values @a lhs and @a rhs are equal
+
+ @complexity Linear.
+
+ @liveexample{The example demonstrates comparing several JSON
+ types.,operator__equal}
+ */
+ friend bool operator==(const_reference lhs, const_reference rhs) noexcept
+ {
+ const auto lhs_type = lhs.type();
+ const auto rhs_type = rhs.type();
+
+ if (lhs_type == rhs_type)
+ {
+ switch (lhs_type)
+ {
+ case (value_t::array):
+ return *lhs.m_value.array == *rhs.m_value.array;
+ case (value_t::object):
+ return *lhs.m_value.object == *rhs.m_value.object;
+ case (value_t::null):
+ return true;
+ case (value_t::string):
+ return *lhs.m_value.string == *rhs.m_value.string;
+ case (value_t::boolean):
+ return lhs.m_value.boolean == rhs.m_value.boolean;
+ case (value_t::number_integer):
+ return lhs.m_value.number_integer == rhs.m_value.number_integer;
+ case (value_t::number_float):
+ return approx(lhs.m_value.number_float, rhs.m_value.number_float);
+ case (value_t::discarded):
+ return false;
+ }
+ }
+ else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float)
+ {
+ return approx(static_cast<number_float_t>(lhs.m_value.number_integer),
+ rhs.m_value.number_float);
+ }
+ else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer)
+ {
+ return approx(lhs.m_value.number_float,
+ static_cast<number_float_t>(rhs.m_value.number_integer));
+ }
+ return false;
+ }
+
+ /*!
+ @brief comparison: equal
+
+ The functions compares the given JSON value against a null pointer. As the
+ null pointer can be used to initialize a JSON value to null, a comparison
+ of JSON value @a v with a null pointer should be equivalent to call
+ `v.is_null()`.
+
+ @param[in] v JSON value to consider
+ @return whether @a v is null
+
+ @complexity Constant.
+
+ @liveexample{The example compares several JSON types to the null pointer.
+ ,operator__equal__nullptr_t}
+ */
+ friend bool operator==(const_reference v, std::nullptr_t) noexcept
+ {
+ return v.is_null();
+ }
+
+ /*!
+ @brief comparison: equal
+ @copydoc operator==(const_reference, std::nullptr_t)
+ */
+ friend bool operator==(std::nullptr_t, const_reference v) noexcept
+ {
+ return v.is_null();
+ }
+
+ /*!
+ @brief comparison: not equal
+
+ Compares two JSON values for inequality by calculating `not (lhs == rhs)`.
+
+ @param[in] lhs first JSON value to consider
+ @param[in] rhs second JSON value to consider
+ @return whether the values @a lhs and @a rhs are not equal
+
+ @complexity Linear.
+
+ @liveexample{The example demonstrates comparing several JSON
+ types.,operator__notequal}
+ */
+ friend bool operator!=(const_reference lhs, const_reference rhs) noexcept
+ {
+ return not (lhs == rhs);
+ }
+
+ /*!
+ @brief comparison: not equal
+
+ The functions compares the given JSON value against a null pointer. As the
+ null pointer can be used to initialize a JSON value to null, a comparison
+ of JSON value @a v with a null pointer should be equivalent to call
+ `not v.is_null()`.
+
+ @param[in] v JSON value to consider
+ @return whether @a v is not null
+
+ @complexity Constant.
+
+ @liveexample{The example compares several JSON types to the null pointer.
+ ,operator__notequal__nullptr_t}
+ */
+ friend bool operator!=(const_reference v, std::nullptr_t) noexcept
+ {
+ return not v.is_null();
+ }
+
+ /*!
+ @brief comparison: not equal
+ @copydoc operator!=(const_reference, std::nullptr_t)
+ */
+ friend bool operator!=(std::nullptr_t, const_reference v) noexcept
+ {
+ return not v.is_null();
+ }
+
+ /*!
+ @brief comparison: less than
+
+ Compares whether one JSON value @a lhs is less than another JSON value @a
+ rhs according to the following rules:
+ - If @a lhs and @a rhs have the same type, the values are compared using
+ the default `<` operator.
+ - Integer and floating-point numbers are automatically converted before
+ comparison
+ - In case @a lhs and @a rhs have different types, the values are ignored
+ and the order of the types is considered, see
+ @ref operator<(const value_t, const value_t).
+
+ @param[in] lhs first JSON value to consider
+ @param[in] rhs second JSON value to consider
+ @return whether @a lhs is less than @a rhs
+
+ @complexity Linear.
+
+ @liveexample{The example demonstrates comparing several JSON
+ types.,operator__less}
+ */
+ friend bool operator<(const_reference lhs, const_reference rhs) noexcept
+ {
+ const auto lhs_type = lhs.type();
+ const auto rhs_type = rhs.type();
+
+ if (lhs_type == rhs_type)
+ {
+ switch (lhs_type)
+ {
+ case (value_t::array):
+ return *lhs.m_value.array < *rhs.m_value.array;
+ case (value_t::object):
+ return *lhs.m_value.object < *rhs.m_value.object;
+ case (value_t::null):
+ return false;
+ case (value_t::string):
+ return *lhs.m_value.string < *rhs.m_value.string;
+ case (value_t::boolean):
+ return lhs.m_value.boolean < rhs.m_value.boolean;
+ case (value_t::number_integer):
+ return lhs.m_value.number_integer < rhs.m_value.number_integer;
+ case (value_t::number_float):
+ return lhs.m_value.number_float < rhs.m_value.number_float;
+ case (value_t::discarded):
+ return false;
+ }
+ }
+ else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float)
+ {
+ return static_cast<number_float_t>(lhs.m_value.number_integer) <
+ rhs.m_value.number_float;
+ }
+ else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer)
+ {
+ return lhs.m_value.number_float <
+ static_cast<number_float_t>(rhs.m_value.number_integer);
+ }
+
+ // We only reach this line if we cannot compare values. In that case,
+ // we compare types. Note we have to call the operator explicitly,
+ // because MSVC has problems otherwise.
+ return operator<(lhs_type, rhs_type);
+ }
+
+ /*!
+ @brief comparison: less than or equal
+
+ Compares whether one JSON value @a lhs is less than or equal to another
+ JSON value by calculating `not (rhs < lhs)`.
+
+ @param[in] lhs first JSON value to consider
+ @param[in] rhs second JSON value to consider
+ @return whether @a lhs is less than or equal to @a rhs
+
+ @complexity Linear.
+
+ @liveexample{The example demonstrates comparing several JSON
+ types.,operator__greater}
+ */
+ friend bool operator<=(const_reference lhs, const_reference rhs) noexcept
+ {
+ return not (rhs < lhs);
+ }
+
+ /*!
+ @brief comparison: greater than
+
+ Compares whether one JSON value @a lhs is greater than another
+ JSON value by calculating `not (lhs <= rhs)`.
+
+ @param[in] lhs first JSON value to consider
+ @param[in] rhs second JSON value to consider
+ @return whether @a lhs is greater than to @a rhs
+
+ @complexity Linear.
+
+ @liveexample{The example demonstrates comparing several JSON
+ types.,operator__lessequal}
+ */
+ friend bool operator>(const_reference lhs, const_reference rhs) noexcept
+ {
+ return not (lhs <= rhs);
+ }
+
+ /*!
+ @brief comparison: greater than or equal
+
+ Compares whether one JSON value @a lhs is greater than or equal to another
+ JSON value by calculating `not (lhs < rhs)`.
+
+ @param[in] lhs first JSON value to consider
+ @param[in] rhs second JSON value to consider
+ @return whether @a lhs is greater than or equal to @a rhs
+
+ @complexity Linear.
+
+ @liveexample{The example demonstrates comparing several JSON
+ types.,operator__greaterequal}
+ */
+ friend bool operator>=(const_reference lhs, const_reference rhs) noexcept
+ {
+ return not (lhs < rhs);
+ }
+
+ /// @}
+
+
+ ///////////////////
+ // serialization //
+ ///////////////////
+
+ /// @name serialization
+ /// @{
+
+ /*!
+ @brief serialize to stream
+
+ Serialize the given JSON value @a j to the output stream @a o. The JSON
+ value will be serialized using the @ref dump member function. The
+ indentation of the output can be controlled with the member variable
+ `width` of the output stream @a o. For instance, using the manipulator
+ `std::setw(4)` on @a o sets the indentation level to `4` and the
+ serialization result is the same as calling `dump(4)`.
+
+ @param[in,out] o stream to serialize to
+ @param[in] j JSON value to serialize
+
+ @return the stream @a o
+
+ @complexity Linear.
+
+ @liveexample{The example below shows the serialization with different
+ parameters to `width` to adjust the indentation level.,operator_serialize}
+ */
+ friend std::ostream& operator<<(std::ostream& o, const basic_json& j)
+ {
+ // read width member and use it as indentation parameter if nonzero
+ const bool pretty_print = (o.width() > 0);
+ const auto indentation = (pretty_print ? o.width() : 0);
+
+ // reset width to 0 for subsequent calls to this stream
+ o.width(0);
+
+ // do the actual serialization
+ j.dump(o, pretty_print, static_cast<unsigned int>(indentation));
+ return o;
+ }
+
+ /*!
+ @brief serialize to stream
+ @copydoc operator<<(std::ostream&, const basic_json&)
+ */
+ friend std::ostream& operator>>(const basic_json& j, std::ostream& o)
+ {
+ return o << j;
+ }
+
+ /// @}
+
+
+ /////////////////////
+ // deserialization //
+ /////////////////////
+
+ /// @name deserialization
+ /// @{
+
+ /*!
+ @brief deserialize from string
+
+ @param[in] s string to read a serialized JSON value from
+ @param[in] cb a parser callback function of type @ref parser_callback_t
+ which is used to control the deserialization by filtering unwanted values
+ (optional)
+
+ @return result of the deserialization
+
+ @complexity Linear in the length of the input. The parser is a predictive
+ LL(1) parser. The complexity can be higher if the parser callback function
+ @a cb has a super-linear complexity.
+
+ @liveexample{The example below demonstrates the parse function with and
+ without callback function.,parse__string__parser_callback_t}
+
+ @sa parse(std::istream&, parser_callback_t) for a version that reads from
+ an input stream
+ */
+ static basic_json parse(const string_t& s, parser_callback_t cb = nullptr)
+ {
+ return parser(s, cb).parse();
+ }
+
+ /*!
+ @brief deserialize from stream
+
+ @param[in,out] i stream to read a serialized JSON value from
+ @param[in] cb a parser callback function of type @ref parser_callback_t
+ which is used to control the deserialization by filtering unwanted values
+ (optional)
+
+ @return result of the deserialization
+
+ @complexity Linear in the length of the input. The parser is a predictive
+ LL(1) parser. The complexity can be higher if the parser callback function
+ @a cb has a super-linear complexity.
+
+ @liveexample{The example below demonstrates the parse function with and
+ without callback function.,parse__istream__parser_callback_t}
+
+ @sa parse(const string_t&, parser_callback_t) for a version that reads
+ from a string
+ */
+ static basic_json parse(std::istream& i, parser_callback_t cb = nullptr)
+ {
+ return parser(i, cb).parse();
+ }
+
+ static basic_json parse(std::istream&& i, parser_callback_t cb = nullptr)
+ {
+ return parser(i, cb).parse();
+ }
+
+ /*!
+ @brief deserialize from stream
+
+ Deserializes an input stream to a JSON value.
+
+ @param[in,out] i input stream to read a serialized JSON value from
+ @param[in,out] j JSON value to write the deserialized input to
+
+ @throw std::invalid_argument in case of parse errors
+
+ @complexity Linear in the length of the input. The parser is a predictive
+ LL(1) parser.
+
+ @liveexample{The example below shows how a JSON value is constructed by
+ reading a serialization from a stream.,operator_deserialize}
+
+ @sa parse(std::istream&, parser_callback_t) for a variant with a parser
+ callback function to filter values while parsing
+ */
+ friend std::istream& operator<<(basic_json& j, std::istream& i)
+ {
+ j = parser(i).parse();
+ return i;
+ }
+
+ /*!
+ @brief deserialize from stream
+ @copydoc operator<<(basic_json&, std::istream&)
+ */
+ friend std::istream& operator>>(std::istream& i, basic_json& j)
+ {
+ j = parser(i).parse();
+ return i;
+ }
+
+ /// @}
+
+
+ private:
+ ///////////////////////////
+ // convenience functions //
+ ///////////////////////////
+
+ /// return the type as string
+ string_t type_name() const
+ {
+ switch (m_type)
+ {
+ case (value_t::null):
+ {
+ return "null";
+ }
+
+ case (value_t::object):
+ {
+ return "object";
+ }
+
+ case (value_t::array):
+ {
+ return "array";
+ }
+
+ case (value_t::string):
+ {
+ return "string";
+ }
+
+ case (value_t::boolean):
+ {
+ return "boolean";
+ }
+
+ case (value_t::discarded):
+ {
+ return "discarded";
+ }
+
+ default:
+ {
+ return "number";
+ }
+ }
+ }
+
+ /*!
+ @brief calculates the extra space to escape a JSON string
+
+ @param[in] s the string to escape
+ @return the number of characters required to escape string @a s
+
+ @complexity Linear in the length of string @a s.
+ */
+ static std::size_t extra_space(const string_t& s) noexcept
+ {
+ std::size_t result = 0;
+
+ for (const auto& c : s)
+ {
+ switch (c)
+ {
+ case '"':
+ case '\\':
+ case '\b':
+ case '\f':
+ case '\n':
+ case '\r':
+ case '\t':
+ {
+ // from c (1 byte) to \x (2 bytes)
+ result += 1;
+ break;
+ }
+
+ default:
+ {
+ if (c >= 0x00 and c <= 0x1f)
+ {
+ // from c (1 byte) to \uxxxx (6 bytes)
+ result += 5;
+ }
+ break;
+ }
+ }
+ }
+
+ return result;
+ }
+
+ /*!
+ @brief escape a string
+
+ Escape a string by replacing certain special characters by a sequence of an
+ escape character (backslash) and another character and other control
+ characters by a sequence of "\u" followed by a four-digit hex
+ representation.
+
+ @param[in] s the string to escape
+ @return the escaped string
+
+ @complexity Linear in the length of string @a s.
+ */
+ static string_t escape_string(const string_t& s) noexcept
+ {
+ const auto space = extra_space(s);
+ if (space == 0)
+ {
+ return s;
+ }
+
+ // create a result string of necessary size
+ string_t result(s.size() + space, '\\');
+ std::size_t pos = 0;
+
+ for (const auto& c : s)
+ {
+ switch (c)
+ {
+ // quotation mark (0x22)
+ case '"':
+ {
+ result[pos + 1] = '"';
+ pos += 2;
+ break;
+ }
+
+ // reverse solidus (0x5c)
+ case '\\':
+ {
+ // nothing to change
+ pos += 2;
+ break;
+ }
+
+ // backspace (0x08)
+ case '\b':
+ {
+ result[pos + 1] = 'b';
+ pos += 2;
+ break;
+ }
+
+ // formfeed (0x0c)
+ case '\f':
+ {
+ result[pos + 1] = 'f';
+ pos += 2;
+ break;
+ }
+
+ // newline (0x0a)
+ case '\n':
+ {
+ result[pos + 1] = 'n';
+ pos += 2;
+ break;
+ }
+
+ // carriage return (0x0d)
+ case '\r':
+ {
+ result[pos + 1] = 'r';
+ pos += 2;
+ break;
+ }
+
+ // horizontal tab (0x09)
+ case '\t':
+ {
+ result[pos + 1] = 't';
+ pos += 2;
+ break;
+ }
+
+ default:
+ {
+ if (c >= 0x00 and c <= 0x1f)
+ {
+ // print character c as \uxxxx
+ sprintf(&result[pos + 1], "u%04x", int(c));
+ pos += 6;
+ // overwrite trailing null character
+ result[pos] = '\\';
+ }
+ else
+ {
+ // all other characters are added as-is
+ result[pos++] = c;
+ }
+ break;
+ }
+ }
+ }
+
+ return result;
+ }
+
+ /*!
+ @brief internal implementation of the serialization function
+
+ This function is called by the public member function dump and organizes
+ the serializaion internally. The indentation level is propagated as
+ additional parameter. In case of arrays and objects, the function is called
+ recursively. Note that
+
+ - strings and object keys are escaped using escape_string()
+ - integer numbers are converted implictly via operator<<
+ - floating-point numbers are converted to a string using "%g" format
+
+ @param[out] o stream to write to
+ @param[in] pretty_print whether the output shall be pretty-printed
+ @param[in] indent_step the indent level
+ @param[in] current_indent the current indent level (only used internally)
+ */
+ void dump(std::ostream& o, const bool pretty_print, const unsigned int indent_step,
+ const unsigned int current_indent = 0) const
+ {
+ // variable to hold indentation for recursive calls
+ unsigned int new_indent = current_indent;
+
+ switch (m_type)
+ {
+ case (value_t::object):
+ {
+ if (m_value.object->empty())
+ {
+ o << "{}";
+ return;
+ }
+
+ o << "{";
+
+ // increase indentation
+ if (pretty_print)
+ {
+ new_indent += indent_step;
+ o << "\n";
+ }
+
+ for (auto i = m_value.object->cbegin(); i != m_value.object->cend(); ++i)
+ {
+ if (i != m_value.object->cbegin())
+ {
+ o << (pretty_print ? ",\n" : ",");
+ }
+ o << string_t(new_indent, ' ') << "\""
+ << escape_string(i->first) << "\":"
+ << (pretty_print ? " " : "");
+ i->second.dump(o, pretty_print, indent_step, new_indent);
+ }
+
+ // decrease indentation
+ if (pretty_print)
+ {
+ new_indent -= indent_step;
+ o << "\n";
+ }
+
+ o << string_t(new_indent, ' ') + "}";
+ return;
+ }
+
+ case (value_t::array):
+ {
+ if (m_value.array->empty())
+ {
+ o << "[]";
+ return;
+ }
+
+ o << "[";
+
+ // increase indentation
+ if (pretty_print)
+ {
+ new_indent += indent_step;
+ o << "\n";
+ }
+
+ for (auto i = m_value.array->cbegin(); i != m_value.array->cend(); ++i)
+ {
+ if (i != m_value.array->cbegin())
+ {
+ o << (pretty_print ? ",\n" : ",");
+ }
+ o << string_t(new_indent, ' ');
+ i->dump(o, pretty_print, indent_step, new_indent);
+ }
+
+ // decrease indentation
+ if (pretty_print)
+ {
+ new_indent -= indent_step;
+ o << "\n";
+ }
+
+ o << string_t(new_indent, ' ') << "]";
+ return;
+ }
+
+ case (value_t::string):
+ {
+ o << string_t("\"") << escape_string(*m_value.string) << "\"";
+ return;
+ }
+
+ case (value_t::boolean):
+ {
+ o << (m_value.boolean ? "true" : "false");
+ return;
+ }
+
+ case (value_t::number_integer):
+ {
+ o << m_value.number_integer;
+ return;
+ }
+
+ case (value_t::number_float):
+ {
+ // 15 digits of precision allows round-trip IEEE 754
+ // string->double->string; to be safe, we read this value from
+ // std::numeric_limits<number_float_t>::digits10
+ o << std::setprecision(std::numeric_limits<number_float_t>::digits10) << m_value.number_float;
+ return;
+ }
+
+ case (value_t::discarded):
+ {
+ o << "<discarded>";
+ return;
+ }
+
+ default:
+ {
+ o << "null";
+ return;
+ }
+ }
+ }
+
+ private:
+ //////////////////////
+ // member variables //
+ //////////////////////
+
+ /// the type of the current element
+ value_t m_type = value_t::null;
+
+ /// the value of the current element
+ json_value m_value = {};
+
+
+ private:
+ ///////////////
+ // iterators //
+ ///////////////
+
+ /*!
+ @brief an iterator for primitive JSON types
+
+ This class models an iterator for primitive JSON types (boolean, number,
+ string). It's only purpose is to allow the iterator/const_iterator classes
+ to "iterate" over primitive values. Internally, the iterator is modeled by
+ a `difference_type` variable. Value begin_value (`0`) models the begin,
+ end_value (`1`) models past the end.
+ */
+ class primitive_iterator_t
+ {
+ public:
+ /// set iterator to a defined beginning
+ void set_begin()
+ {
+ m_it = begin_value;
+ }
+
+ /// set iterator to a defined past the end
+ void set_end()
+ {
+ m_it = end_value;
+ }
+
+ /// return whether the iterator can be dereferenced
+ bool is_begin() const
+ {
+ return (m_it == begin_value);
+ }
+
+ /// return whether the iterator is at end
+ bool is_end() const
+ {
+ return (m_it == end_value);
+ }
+
+ /// return reference to the value to change and compare
+ operator difference_type& ()
+ {
+ return m_it;
+ }
+
+ /// return value to compare
+ operator difference_type () const
+ {
+ return m_it;
+ }
+
+ private:
+ static constexpr difference_type begin_value = 0;
+ static constexpr difference_type end_value = begin_value + 1;
+
+ /// iterator as signed integer type
+ difference_type m_it = std::numeric_limits<std::ptrdiff_t>::min();
+ };
+
+ /*!
+ @brief an iterator value
+
+ @note This structure could easily be a union, but MSVC currently does not
+ allow unions members with complex constructors, see
+ https://github.com/nlohmann/json/pull/105.
+ */
+ struct internal_iterator
+ {
+ /// iterator for JSON objects
+ typename object_t::iterator object_iterator;
+ /// iterator for JSON arrays
+ typename array_t::iterator array_iterator;
+ /// generic iterator for all other types
+ primitive_iterator_t primitive_iterator;
+
+ /// create an uninitialized internal_iterator
+ internal_iterator()
+ : object_iterator(), array_iterator(), primitive_iterator()
+ {}
+ };
+
+ public:
+ /*!
+ @brief a const random access iterator for the @ref basic_json class
+
+ This class implements a const iterator for the @ref basic_json class. From
+ this class, the @ref iterator class is derived.
+
+ @requirement The class satisfies the following concept requirements:
+ - [RandomAccessIterator](http://en.cppreference.com/w/cpp/concept/RandomAccessIterator):
+ The iterator that can be moved to point (forward and backward) to any
+ element in constant time.
+ */
+ class const_iterator : public std::iterator<std::random_access_iterator_tag, const basic_json>
+ {
+ /// allow basic_json to access private members
+ friend class basic_json;
+
+ public:
+ /// the type of the values when the iterator is dereferenced
+ using value_type = typename basic_json::value_type;
+ /// a type to represent differences between iterators
+ using difference_type = typename basic_json::difference_type;
+ /// defines a pointer to the type iterated over (value_type)
+ using pointer = typename basic_json::const_pointer;
+ /// defines a reference to the type iterated over (value_type)
+ using reference = typename basic_json::const_reference;
+ /// the category of the iterator
+ using iterator_category = std::bidirectional_iterator_tag;
+
+ /// default constructor
+ const_iterator() = default;
+
+ /// constructor for a given JSON instance
+ const_iterator(pointer object) : m_object(object)
+ {
+ switch (m_object->m_type)
+ {
+ case (basic_json::value_t::object):
+ {
+ m_it.object_iterator = typename object_t::iterator();
+ break;
+ }
+ case (basic_json::value_t::array):
+ {
+ m_it.array_iterator = typename array_t::iterator();
+ break;
+ }
+ default:
+ {
+ m_it.primitive_iterator = primitive_iterator_t();
+ break;
+ }
+ }
+ }
+
+ /// copy constructor given a nonconst iterator
+ const_iterator(const iterator& other) : m_object(other.m_object)
+ {
+ switch (m_object->m_type)
+ {
+ case (basic_json::value_t::object):
+ {
+ m_it.object_iterator = other.m_it.object_iterator;
+ break;
+ }
+
+ case (basic_json::value_t::array):
+ {
+ m_it.array_iterator = other.m_it.array_iterator;
+ break;
+ }
+
+ default:
+ {
+ m_it.primitive_iterator = other.m_it.primitive_iterator;
+ break;
+ }
+ }
+ }
+
+ /// copy constructor
+ const_iterator(const const_iterator& other) noexcept
+ : m_object(other.m_object), m_it(other.m_it)
+ {}
+
+ /// copy assignment
+ const_iterator& operator=(const_iterator other) noexcept(
+ std::is_nothrow_move_constructible<pointer>::value and
+ std::is_nothrow_move_assignable<pointer>::value and
+ std::is_nothrow_move_constructible<internal_iterator>::value and
+ std::is_nothrow_move_assignable<internal_iterator>::value
+ )
+ {
+ std::swap(m_object, other.m_object);
+ std::swap(m_it, other.m_it);
+ return *this;
+ }
+
+ private:
+ /// set the iterator to the first value
+ void set_begin()
+ {
+ switch (m_object->m_type)
+ {
+ case (basic_json::value_t::object):
+ {
+ m_it.object_iterator = m_object->m_value.object->begin();
+ break;
+ }
+
+ case (basic_json::value_t::array):
+ {
+ m_it.array_iterator = m_object->m_value.array->begin();
+ break;
+ }
+
+ case (basic_json::value_t::null):
+ {
+ // set to end so begin()==end() is true: null is empty
+ m_it.primitive_iterator.set_end();
+ break;
+ }
+
+ default:
+ {
+ m_it.primitive_iterator.set_begin();
+ break;
+ }
+ }
+ }
+
+ /// set the iterator past the last value
+ void set_end()
+ {
+ switch (m_object->m_type)
+ {
+ case (basic_json::value_t::object):
+ {
+ m_it.object_iterator = m_object->m_value.object->end();
+ break;
+ }
+
+ case (basic_json::value_t::array):
+ {
+ m_it.array_iterator = m_object->m_value.array->end();
+ break;
+ }
+
+ default:
+ {
+ m_it.primitive_iterator.set_end();
+ break;
+ }
+ }
+ }
+
+ public:
+ /// return a reference to the value pointed to by the iterator
+ reference operator*() const
+ {
+ switch (m_object->m_type)
+ {
+ case (basic_json::value_t::object):
+ {
+ return m_it.object_iterator->second;
+ }
+
+ case (basic_json::value_t::array):
+ {
+ return *m_it.array_iterator;
+ }
+
+ case (basic_json::value_t::null):
+ {
+ throw std::out_of_range("cannot get value");
+ }
+
+ default:
+ {
+ if (m_it.primitive_iterator.is_begin())
+ {
+ return *m_object;
+ }
+ else
+ {
+ throw std::out_of_range("cannot get value");
+ }
+ }
+ }
+ }
+
+ /// dereference the iterator
+ pointer operator->() const
+ {
+ switch (m_object->m_type)
+ {
+ case (basic_json::value_t::object):
+ {
+ return &(m_it.object_iterator->second);
+ }
+
+ case (basic_json::value_t::array):
+ {
+ return &*m_it.array_iterator;
+ }
+
+ default:
+ {
+ if (m_it.primitive_iterator.is_begin())
+ {
+ return m_object;
+ }
+ else
+ {
+ throw std::out_of_range("cannot get value");
+ }
+ }
+ }
+ }
+
+ /// post-increment (it++)
+ const_iterator operator++(int)
+ {
+ auto result = *this;
+ ++(*this);
+
+ return result;
+ }
+
+ /// pre-increment (++it)
+ const_iterator& operator++()
+ {
+ switch (m_object->m_type)
+ {
+ case (basic_json::value_t::object):
+ {
+ ++m_it.object_iterator;
+ break;
+ }
+
+ case (basic_json::value_t::array):
+ {
+ ++m_it.array_iterator;
+ break;
+ }
+
+ default:
+ {
+ ++m_it.primitive_iterator;
+ break;
+ }
+ }
+
+ return *this;
+ }
+
+ /// post-decrement (it--)
+ const_iterator operator--(int)
+ {
+ auto result = *this;
+ --(*this);
+
+ return result;
+ }
+
+ /// pre-decrement (--it)
+ const_iterator& operator--()
+ {
+ switch (m_object->m_type)
+ {
+ case (basic_json::value_t::object):
+ {
+ --m_it.object_iterator;
+ break;
+ }
+
+ case (basic_json::value_t::array):
+ {
+ --m_it.array_iterator;
+ break;
+ }
+
+ default:
+ {
+ --m_it.primitive_iterator;
+ break;
+ }
+ }
+
+ return *this;
+ }
+
+ /// comparison: equal
+ bool operator==(const const_iterator& other) const
+ {
+ // if objects are not the same, the comparison is undefined
+ if (m_object != other.m_object)
+ {
+ throw std::domain_error("cannot compare iterators of different containers");
+ }
+
+ switch (m_object->m_type)
+ {
+ case (basic_json::value_t::object):
+ {
+ return (m_it.object_iterator == other.m_it.object_iterator);
+ }
+
+ case (basic_json::value_t::array):
+ {
+ return (m_it.array_iterator == other.m_it.array_iterator);
+ }
+
+ default:
+ {
+ return (m_it.primitive_iterator == other.m_it.primitive_iterator);
+ }
+ }
+ }
+
+ /// comparison: not equal
+ bool operator!=(const const_iterator& other) const
+ {
+ return not operator==(other);
+ }
+
+ /// comparison: smaller
+ bool operator<(const const_iterator& other) const
+ {
+ // if objects are not the same, the comparison is undefined
+ if (m_object != other.m_object)
+ {
+ throw std::domain_error("cannot compare iterators of different containers");
+ }
+
+ switch (m_object->m_type)
+ {
+ case (basic_json::value_t::object):
+ {
+ throw std::domain_error("cannot use operator< for object iterators");
+ }
+
+ case (basic_json::value_t::array):
+ {
+ return (m_it.array_iterator < other.m_it.array_iterator);
+ }
+
+ default:
+ {
+ return (m_it.primitive_iterator < other.m_it.primitive_iterator);
+ }
+ }
+ }
+
+ /// comparison: less than or equal
+ bool operator<=(const const_iterator& other) const
+ {
+ return not other.operator < (*this);
+ }
+
+ /// comparison: greater than
+ bool operator>(const const_iterator& other) const
+ {
+ return not operator<=(other);
+ }
+
+ /// comparison: greater than or equal
+ bool operator>=(const const_iterator& other) const
+ {
+ return not operator<(other);
+ }
+
+ /// add to iterator
+ const_iterator& operator+=(difference_type i)
+ {
+ switch (m_object->m_type)
+ {
+ case (basic_json::value_t::object):
+ {
+ throw std::domain_error("cannot use operator+= for object iterators");
+ }
+
+ case (basic_json::value_t::array):
+ {
+ m_it.array_iterator += i;
+ break;
+ }
+
+ default:
+ {
+ m_it.primitive_iterator += i;
+ break;
+ }
+ }
+
+ return *this;
+ }
+
+ /// subtract from iterator
+ const_iterator& operator-=(difference_type i)
+ {
+ return operator+=(-i);
+ }
+
+ /// add to iterator
+ const_iterator operator+(difference_type i)
+ {
+ auto result = *this;
+ result += i;
+ return result;
+ }
+
+ /// subtract from iterator
+ const_iterator operator-(difference_type i)
+ {
+ auto result = *this;
+ result -= i;
+ return result;
+ }
+
+ /// return difference
+ difference_type operator-(const const_iterator& other) const
+ {
+ switch (m_object->m_type)
+ {
+ case (basic_json::value_t::object):
+ {
+ throw std::domain_error("cannot use operator- for object iterators");
+ }
+
+ case (basic_json::value_t::array):
+ {
+ return m_it.array_iterator - other.m_it.array_iterator;
+ }
+
+ default:
+ {
+ return m_it.primitive_iterator - other.m_it.primitive_iterator;
+ }
+ }
+ }
+
+ /// access to successor
+ reference operator[](difference_type n) const
+ {
+ switch (m_object->m_type)
+ {
+ case (basic_json::value_t::object):
+ {
+ throw std::domain_error("cannot use operator[] for object iterators");
+ }
+
+ case (basic_json::value_t::array):
+ {
+ return *(m_it.array_iterator + n);
+ }
+
+ case (basic_json::value_t::null):
+ {
+ throw std::out_of_range("cannot get value");
+ }
+
+ default:
+ {
+ if (m_it.primitive_iterator == -n)
+ {
+ return *m_object;
+ }
+ else
+ {
+ throw std::out_of_range("cannot get value");
+ }
+ }
+ }
+ }
+
+ /// return the key of an object iterator
+ typename object_t::key_type key() const
+ {
+ switch (m_object->m_type)
+ {
+ case (basic_json::value_t::object):
+ {
+ return m_it.object_iterator->first;
+ }
+
+ default:
+ {
+ throw std::domain_error("cannot use key() for non-object iterators");
+ }
+ }
+ }
+
+ /// return the value of an iterator
+ reference value() const
+ {
+ return operator*();
+ }
+
+ private:
+ /// associated JSON instance
+ pointer m_object = nullptr;
+ /// the actual iterator of the associated instance
+ internal_iterator m_it = internal_iterator();
+ };
+
+ /*!
+ @brief a mutable random access iterator for the @ref basic_json class
+
+ @requirement The class satisfies the following concept requirements:
+ - [RandomAccessIterator](http://en.cppreference.com/w/cpp/concept/RandomAccessIterator):
+ The iterator that can be moved to point (forward and backward) to any
+ element in constant time.
+ - [OutputIterator](http://en.cppreference.com/w/cpp/concept/OutputIterator):
+ It is possible to write to the pointed-to element.
+ */
+ class iterator : public const_iterator
+ {
+ public:
+ using base_iterator = const_iterator;
+ using pointer = typename basic_json::pointer;
+ using reference = typename basic_json::reference;
+
+ /// default constructor
+ iterator() = default;
+
+ /// constructor for a given JSON instance
+ iterator(pointer object) noexcept : base_iterator(object)
+ {}
+
+ /// copy constructor
+ iterator(const iterator& other) noexcept
+ : base_iterator(other)
+ {}
+
+ /// copy assignment
+ iterator& operator=(iterator other) noexcept(
+ std::is_nothrow_move_constructible<pointer>::value and
+ std::is_nothrow_move_assignable<pointer>::value and
+ std::is_nothrow_move_constructible<internal_iterator>::value and
+ std::is_nothrow_move_assignable<internal_iterator>::value
+ )
+ {
+ base_iterator::operator=(other);
+ return *this;
+ }
+
+ /// return a reference to the value pointed to by the iterator
+ reference operator*()
+ {
+ return const_cast<reference>(base_iterator::operator*());
+ }
+
+ /// dereference the iterator
+ pointer operator->()
+ {
+ return const_cast<pointer>(base_iterator::operator->());
+ }
+
+ /// post-increment (it++)
+ iterator operator++(int)
+ {
+ iterator result = *this;
+ base_iterator::operator++();
+ return result;
+ }
+
+ /// pre-increment (++it)
+ iterator& operator++()
+ {
+ base_iterator::operator++();
+ return *this;
+ }
+
+ /// post-decrement (it--)
+ iterator operator--(int)
+ {
+ iterator result = *this;
+ base_iterator::operator--();
+ return result;
+ }
+
+ /// pre-decrement (--it)
+ iterator& operator--()
+ {
+ base_iterator::operator--();
+ return *this;
+ }
+
+ /// add to iterator
+ iterator& operator+=(difference_type i)
+ {
+ base_iterator::operator+=(i);
+ return *this;
+ }
+
+ /// subtract from iterator
+ iterator& operator-=(difference_type i)
+ {
+ base_iterator::operator-=(i);
+ return *this;
+ }
+
+ /// add to iterator
+ iterator operator+(difference_type i)
+ {
+ auto result = *this;
+ result += i;
+ return result;
+ }
+
+ /// subtract from iterator
+ iterator operator-(difference_type i)
+ {
+ auto result = *this;
+ result -= i;
+ return result;
+ }
+
+ difference_type operator-(const iterator& other) const
+ {
+ return base_iterator::operator-(other);
+ }
+
+ /// access to successor
+ reference operator[](difference_type n) const
+ {
+ return const_cast<reference>(base_iterator::operator[](n));
+ }
+
+ /// return the value of an iterator
+ reference value() const
+ {
+ return const_cast<reference>(base_iterator::value());
+ }
+ };
+
+ /*!
+ @brief a template for a reverse iterator class
+
+ @tparam Base the base iterator type to reverse. Valid types are @ref
+ iterator (to create @ref reverse_iterator) and @ref const_iterator (to
+ create @ref const_reverse_iterator).
+
+ @requirement The class satisfies the following concept requirements:
+ - [RandomAccessIterator](http://en.cppreference.com/w/cpp/concept/RandomAccessIterator):
+ The iterator that can be moved to point (forward and backward) to any
+ element in constant time.
+ - [OutputIterator](http://en.cppreference.com/w/cpp/concept/OutputIterator):
+ It is possible to write to the pointed-to element (only if @a Base is
+ @ref iterator).
+ */
+ template<typename Base>
+ class json_reverse_iterator : public std::reverse_iterator<Base>
+ {
+ public:
+ /// shortcut to the reverse iterator adaptor
+ using base_iterator = std::reverse_iterator<Base>;
+ /// the reference type for the pointed-to element
+ using reference = typename Base::reference;
+
+ /// create reverse iterator from iterator
+ json_reverse_iterator(const typename base_iterator::iterator_type& it)
+ : base_iterator(it) {}
+
+ /// create reverse iterator from base class
+ json_reverse_iterator(const base_iterator& it) : base_iterator(it) {}
+
+ /// post-increment (it++)
+ json_reverse_iterator operator++(int)
+ {
+ return base_iterator::operator++(1);
+ }
+
+ /// pre-increment (++it)
+ json_reverse_iterator& operator++()
+ {
+ base_iterator::operator++();
+ return *this;
+ }
+
+ /// post-decrement (it--)
+ json_reverse_iterator operator--(int)
+ {
+ return base_iterator::operator--(1);
+ }
+
+ /// pre-decrement (--it)
+ json_reverse_iterator& operator--()
+ {
+ base_iterator::operator--();
+ return *this;
+ }
+
+ /// add to iterator
+ json_reverse_iterator& operator+=(difference_type i)
+ {
+ base_iterator::operator+=(i);
+ return *this;
+ }
+
+ /// add to iterator
+ json_reverse_iterator operator+(difference_type i) const
+ {
+ auto result = *this;
+ result += i;
+ return result;
+ }
+
+ /// subtract from iterator
+ json_reverse_iterator operator-(difference_type i) const
+ {
+ auto result = *this;
+ result -= i;
+ return result;
+ }
+
+ /// return difference
+ difference_type operator-(const json_reverse_iterator& other) const
+ {
+ return this->base() - other.base();
+ }
+
+ /// access to successor
+ reference operator[](difference_type n) const
+ {
+ return *(this->operator+(n));
+ }
+
+ /// return the key of an object iterator
+ typename object_t::key_type key() const
+ {
+ auto it = --this->base();
+ return it.key();
+ }
+
+ /// return the value of an iterator
+ reference value() const
+ {
+ auto it = --this->base();
+ return it.operator * ();
+ }
+ };
+
+ /*!
+ @brief wrapper to access iterator member functions in range-based for
+
+ This class allows to access @ref key() and @ref value() during range-based
+ for loops. In these loops, a reference to the JSON values is returned, so
+ there is no access to the underlying iterator.
+ */
+ class iterator_wrapper
+ {
+ private:
+ /// the container to iterate
+ basic_json& container;
+ /// the type of the iterator to use while iteration
+ using json_iterator = decltype(std::begin(container));
+
+ /// internal iterator wrapper
+ class iterator_wrapper_internal
+ {
+ private:
+ /// the iterator
+ json_iterator anchor;
+ /// an index for arrays
+ size_t array_index = 0;
+
+ public:
+ /// construct wrapper given an iterator
+ iterator_wrapper_internal(json_iterator i) : anchor(i)
+ {}
+
+ /// dereference operator (needed for range-based for)
+ iterator_wrapper_internal& operator*()
+ {
+ return *this;
+ }
+
+ /// increment operator (needed for range-based for)
+ iterator_wrapper_internal& operator++()
+ {
+ ++anchor;
+ ++array_index;
+
+ return *this;
+ }
+
+ /// inequality operator (needed for range-based for)
+ bool operator!= (const iterator_wrapper_internal& o)
+ {
+ return anchor != o.anchor;
+ }
+
+ /// return key of the iterator
+ typename basic_json::string_t key() const
+ {
+ switch (anchor.m_object->type())
+ {
+ /// use integer array index as key
+ case (value_t::array):
+ {
+ return std::to_string(array_index);
+ }
+
+ /// use key from the object
+ case (value_t::object):
+ {
+ return anchor.key();
+ }
+
+ /// use an empty key for all primitive types
+ default:
+ {
+ return "";
+ }
+ }
+ }
+
+ /// return value of the iterator
+ typename json_iterator::reference value() const
+ {
+ return anchor.value();
+ }
+ };
+
+ public:
+ /// construct iterator wrapper from a container
+ iterator_wrapper(basic_json& cont)
+ : container(cont)
+ {}
+
+ /// return iterator begin (needed for range-based for)
+ iterator_wrapper_internal begin()
+ {
+ return iterator_wrapper_internal(container.begin());
+ }
+
+ /// return iterator end (needed for range-based for)
+ iterator_wrapper_internal end()
+ {
+ return iterator_wrapper_internal(container.end());
+ }
+ };
+
+ private:
+ //////////////////////
+ // lexer and parser //
+ //////////////////////
+
+ /*!
+ @brief lexical analysis
+
+ This class organizes the lexical analysis during JSON deserialization. The
+ core of it is a scanner generated by re2c <http://re2c.org> that processes
+ a buffer and recognizes tokens according to RFC 7159.
+ */
+ class lexer
+ {
+ public:
+ /// token types for the parser
+ enum class token_type
+ {
+ uninitialized, ///< indicating the scanner is uninitialized
+ literal_true, ///< the "true" literal
+ literal_false, ///< the "false" literal
+ literal_null, ///< the "null" literal
+ value_string, ///< a string - use get_string() for actual value
+ value_number, ///< a number - use get_number() for actual value
+ begin_array, ///< the character for array begin "["
+ begin_object, ///< the character for object begin "{"
+ end_array, ///< the character for array end "]"
+ end_object, ///< the character for object end "}"
+ name_separator, ///< the name separator ":"
+ value_separator, ///< the value separator ","
+ parse_error, ///< indicating a parse error
+ end_of_input ///< indicating the end of the input buffer
+ };
+
+ /// the char type to use in the lexer
+ using lexer_char_t = unsigned char;
+
+ /// constructor with a given buffer
+ explicit lexer(const string_t& s) noexcept
+ : m_stream(nullptr), m_buffer(s)
+ {
+ m_content = reinterpret_cast<const lexer_char_t*>(s.c_str());
+ m_start = m_cursor = m_content;
+ m_limit = m_content + s.size();
+ }
+ explicit lexer(std::istream* s) noexcept
+ : m_stream(s), m_buffer()
+ {
+ getline(*m_stream, m_buffer);
+ m_content = reinterpret_cast<const lexer_char_t*>(m_buffer.c_str());
+ m_start = m_cursor = m_content;
+ m_limit = m_content + m_buffer.size();
+ }
+
+ /// default constructor
+ lexer() = default;
+
+ // switch of unwanted functions
+ lexer(const lexer&) = delete;
+ lexer operator=(const lexer&) = delete;
+
+ /*!
+ @brief create a string from a Unicode code point
+
+ @param[in] codepoint1 the code point (can be high surrogate)
+ @param[in] codepoint2 the code point (can be low surrogate or 0)
+ @return string representation of the code point
+ @throw std::out_of_range if code point is >0x10ffff
+ @throw std::invalid_argument if the low surrogate is invalid
+
+ @see <http://en.wikipedia.org/wiki/UTF-8#Sample_code>
+ */
+ static string_t to_unicode(const std::size_t codepoint1,
+ const std::size_t codepoint2 = 0)
+ {
+ string_t result;
+
+ // calculate the codepoint from the given code points
+ std::size_t codepoint = codepoint1;
+
+ // check if codepoint1 is a high surrogate
+ if (codepoint1 >= 0xD800 and codepoint1 <= 0xDBFF)
+ {
+ // check if codepoint2 is a low surrogate
+ if (codepoint2 >= 0xDC00 and codepoint2 <= 0xDFFF)
+ {
+ codepoint =
+ // high surrogate occupies the most significant 22 bits
+ (codepoint1 << 10)
+ // low surrogate occupies the least significant 15 bits
+ + codepoint2
+ // there is still the 0xD800, 0xDC00 and 0x10000 noise
+ // in the result so we have to substract with:
+ // (0xD800 << 10) + DC00 - 0x10000 = 0x35FDC00
+ - 0x35FDC00;
+ }
+ else
+ {
+ throw std::invalid_argument("missing or wrong low surrogate");
+ }
+ }
+
+ if (codepoint < 0x80)
+ {
+ // 1-byte characters: 0xxxxxxx (ASCII)
+ result.append(1, static_cast<typename string_t::value_type>(codepoint));
+ }
+ else if (codepoint <= 0x7ff)
+ {
+ // 2-byte characters: 110xxxxx 10xxxxxx
+ result.append(1, static_cast<typename string_t::value_type>(0xC0 | ((codepoint >> 6) & 0x1F)));
+ result.append(1, static_cast<typename string_t::value_type>(0x80 | (codepoint & 0x3F)));
+ }
+ else if (codepoint <= 0xffff)
+ {
+ // 3-byte characters: 1110xxxx 10xxxxxx 10xxxxxx
+ result.append(1, static_cast<typename string_t::value_type>(0xE0 | ((codepoint >> 12) & 0x0F)));
+ result.append(1, static_cast<typename string_t::value_type>(0x80 | ((codepoint >> 6) & 0x3F)));
+ result.append(1, static_cast<typename string_t::value_type>(0x80 | (codepoint & 0x3F)));
+ }
+ else if (codepoint <= 0x10ffff)
+ {
+ // 4-byte characters: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
+ result.append(1, static_cast<typename string_t::value_type>(0xF0 | ((codepoint >> 18) & 0x07)));
+ result.append(1, static_cast<typename string_t::value_type>(0x80 | ((codepoint >> 12) & 0x3F)));
+ result.append(1, static_cast<typename string_t::value_type>(0x80 | ((codepoint >> 6) & 0x3F)));
+ result.append(1, static_cast<typename string_t::value_type>(0x80 | (codepoint & 0x3F)));
+ }
+ else
+ {
+ throw std::out_of_range("code points above 0x10FFFF are invalid");
+ }
+
+ return result;
+ }
+
+ /// return name of values of type token_type
+ static std::string token_type_name(token_type t)
+ {
+ switch (t)
+ {
+ case (token_type::uninitialized):
+ return "<uninitialized>";
+ case (token_type::literal_true):
+ return "true literal";
+ case (token_type::literal_false):
+ return "false literal";
+ case (token_type::literal_null):
+ return "null literal";
+ case (token_type::value_string):
+ return "string literal";
+ case (token_type::value_number):
+ return "number literal";
+ case (token_type::begin_array):
+ return "[";
+ case (token_type::begin_object):
+ return "{";
+ case (token_type::end_array):
+ return "]";
+ case (token_type::end_object):
+ return "}";
+ case (token_type::name_separator):
+ return ":";
+ case (token_type::value_separator):
+ return ",";
+ case (token_type::end_of_input):
+ return "<end of input>";
+ default:
+ return "<parse error>";
+ }
+ }
+
+ /*!
+ This function implements a scanner for JSON. It is specified using
+ regular expressions that try to follow RFC 7159 as close as possible.
+ These regular expressions are then translated into a deterministic
+ finite automaton (DFA) by the tool re2c <http://re2c.org>. As a result,
+ the translated code for this function consists of a large block of code
+ with goto jumps.
+
+ @return the class of the next token read from the buffer
+ */
+ token_type scan() noexcept
+ {
+ // pointer for backtracking information
+ m_marker = nullptr;
+
+ // remember the begin of the token
+ m_start = m_cursor;
+
+
+ {
+ lexer_char_t yych;
+ unsigned int yyaccept = 0;
+ static const unsigned char yybm[] =
+ {
+ 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 32, 32, 0, 0, 32, 0, 0,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 96, 64, 0, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 192, 192, 192, 192, 192, 192, 192, 192,
+ 192, 192, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 0, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64,
+ };
+
+ if ((m_limit - m_cursor) < 5)
+ {
+ yyfill(); // LCOV_EXCL_LINE;
+ }
+ yych = *m_cursor;
+ if (yych <= '9')
+ {
+ if (yych <= ' ')
+ {
+ if (yych <= '\n')
+ {
+ if (yych <= 0x00)
+ {
+ goto basic_json_parser_27;
+ }
+ if (yych <= 0x08)
+ {
+ goto basic_json_parser_29;
+ }
+ if (yych >= '\n')
+ {
+ goto basic_json_parser_4;
+ }
+ }
+ else
+ {
+ if (yych == '\r')
+ {
+ goto basic_json_parser_2;
+ }
+ if (yych <= 0x1F)
+ {
+ goto basic_json_parser_29;
+ }
+ }
+ }
+ else
+ {
+ if (yych <= ',')
+ {
+ if (yych == '"')
+ {
+ goto basic_json_parser_26;
+ }
+ if (yych <= '+')
+ {
+ goto basic_json_parser_29;
+ }
+ goto basic_json_parser_14;
+ }
+ else
+ {
+ if (yych <= '-')
+ {
+ goto basic_json_parser_22;
+ }
+ if (yych <= '/')
+ {
+ goto basic_json_parser_29;
+ }
+ if (yych <= '0')
+ {
+ goto basic_json_parser_23;
+ }
+ goto basic_json_parser_25;
+ }
+ }
+ }
+ else
+ {
+ if (yych <= 'm')
+ {
+ if (yych <= '\\')
+ {
+ if (yych <= ':')
+ {
+ goto basic_json_parser_16;
+ }
+ if (yych == '[')
+ {
+ goto basic_json_parser_6;
+ }
+ goto basic_json_parser_29;
+ }
+ else
+ {
+ if (yych <= ']')
+ {
+ goto basic_json_parser_8;
+ }
+ if (yych == 'f')
+ {
+ goto basic_json_parser_21;
+ }
+ goto basic_json_parser_29;
+ }
+ }
+ else
+ {
+ if (yych <= 'z')
+ {
+ if (yych <= 'n')
+ {
+ goto basic_json_parser_18;
+ }
+ if (yych == 't')
+ {
+ goto basic_json_parser_20;
+ }
+ goto basic_json_parser_29;
+ }
+ else
+ {
+ if (yych <= '{')
+ {
+ goto basic_json_parser_10;
+ }
+ if (yych == '}')
+ {
+ goto basic_json_parser_12;
+ }
+ goto basic_json_parser_29;
+ }
+ }
+ }
+basic_json_parser_2:
+ ++m_cursor;
+ yych = *m_cursor;
+ goto basic_json_parser_5;
+basic_json_parser_3:
+ {
+ return scan();
+ }
+basic_json_parser_4:
+ ++m_cursor;
+ if (m_limit <= m_cursor)
+ {
+ yyfill(); // LCOV_EXCL_LINE;
+ }
+ yych = *m_cursor;
+basic_json_parser_5:
+ if (yybm[0 + yych] & 32)
+ {
+ goto basic_json_parser_4;
+ }
+ goto basic_json_parser_3;
+basic_json_parser_6:
+ ++m_cursor;
+ {
+ return token_type::begin_array;
+ }
+basic_json_parser_8:
+ ++m_cursor;
+ {
+ return token_type::end_array;
+ }
+basic_json_parser_10:
+ ++m_cursor;
+ {
+ return token_type::begin_object;
+ }
+basic_json_parser_12:
+ ++m_cursor;
+ {
+ return token_type::end_object;
+ }
+basic_json_parser_14:
+ ++m_cursor;
+ {
+ return token_type::value_separator;
+ }
+basic_json_parser_16:
+ ++m_cursor;
+ {
+ return token_type::name_separator;
+ }
+basic_json_parser_18:
+ yyaccept = 0;
+ yych = *(m_marker = ++m_cursor);
+ if (yych == 'u')
+ {
+ goto basic_json_parser_59;
+ }
+basic_json_parser_19:
+ {
+ return token_type::parse_error;
+ }
+basic_json_parser_20:
+ yyaccept = 0;
+ yych = *(m_marker = ++m_cursor);
+ if (yych == 'r')
+ {
+ goto basic_json_parser_55;
+ }
+ goto basic_json_parser_19;
+basic_json_parser_21:
+ yyaccept = 0;
+ yych = *(m_marker = ++m_cursor);
+ if (yych == 'a')
+ {
+ goto basic_json_parser_50;
+ }
+ goto basic_json_parser_19;
+basic_json_parser_22:
+ yych = *++m_cursor;
+ if (yych <= '/')
+ {
+ goto basic_json_parser_19;
+ }
+ if (yych <= '0')
+ {
+ goto basic_json_parser_49;
+ }
+ if (yych <= '9')
+ {
+ goto basic_json_parser_40;
+ }
+ goto basic_json_parser_19;
+basic_json_parser_23:
+ yyaccept = 1;
+ yych = *(m_marker = ++m_cursor);
+ if (yych <= 'D')
+ {
+ if (yych == '.')
+ {
+ goto basic_json_parser_42;
+ }
+ }
+ else
+ {
+ if (yych <= 'E')
+ {
+ goto basic_json_parser_43;
+ }
+ if (yych == 'e')
+ {
+ goto basic_json_parser_43;
+ }
+ }
+basic_json_parser_24:
+ {
+ return token_type::value_number;
+ }
+basic_json_parser_25:
+ yyaccept = 1;
+ yych = *(m_marker = ++m_cursor);
+ goto basic_json_parser_41;
+basic_json_parser_26:
+ yyaccept = 0;
+ yych = *(m_marker = ++m_cursor);
+ if (yych <= 0x0F)
+ {
+ goto basic_json_parser_19;
+ }
+ goto basic_json_parser_31;
+basic_json_parser_27:
+ ++m_cursor;
+ {
+ return token_type::end_of_input;
+ }
+basic_json_parser_29:
+ yych = *++m_cursor;
+ goto basic_json_parser_19;
+basic_json_parser_30:
+ ++m_cursor;
+ if (m_limit <= m_cursor)
+ {
+ yyfill(); // LCOV_EXCL_LINE;
+ }
+ yych = *m_cursor;
+basic_json_parser_31:
+ if (yybm[0 + yych] & 64)
+ {
+ goto basic_json_parser_30;
+ }
+ if (yych <= 0x0F)
+ {
+ goto basic_json_parser_32;
+ }
+ if (yych <= '"')
+ {
+ goto basic_json_parser_34;
+ }
+ goto basic_json_parser_33;
+basic_json_parser_32:
+ m_cursor = m_marker;
+ if (yyaccept == 0)
+ {
+ goto basic_json_parser_19;
+ }
+ else
+ {
+ goto basic_json_parser_24;
+ }
+basic_json_parser_33:
+ ++m_cursor;
+ if (m_limit <= m_cursor)
+ {
+ yyfill(); // LCOV_EXCL_LINE;
+ }
+ yych = *m_cursor;
+ if (yych <= 'e')
+ {
+ if (yych <= '/')
+ {
+ if (yych == '"')
+ {
+ goto basic_json_parser_30;
+ }
+ if (yych <= '.')
+ {
+ goto basic_json_parser_32;
+ }
+ goto basic_json_parser_30;
+ }
+ else
+ {
+ if (yych <= '\\')
+ {
+ if (yych <= '[')
+ {
+ goto basic_json_parser_32;
+ }
+ goto basic_json_parser_30;
+ }
+ else
+ {
+ if (yych == 'b')
+ {
+ goto basic_json_parser_30;
+ }
+ goto basic_json_parser_32;
+ }
+ }
+ }
+ else
+ {
+ if (yych <= 'q')
+ {
+ if (yych <= 'f')
+ {
+ goto basic_json_parser_30;
+ }
+ if (yych == 'n')
+ {
+ goto basic_json_parser_30;
+ }
+ goto basic_json_parser_32;
+ }
+ else
+ {
+ if (yych <= 's')
+ {
+ if (yych <= 'r')
+ {
+ goto basic_json_parser_30;
+ }
+ goto basic_json_parser_32;
+ }
+ else
+ {
+ if (yych <= 't')
+ {
+ goto basic_json_parser_30;
+ }
+ if (yych <= 'u')
+ {
+ goto basic_json_parser_36;
+ }
+ goto basic_json_parser_32;
+ }
+ }
+ }
+basic_json_parser_34:
+ ++m_cursor;
+ {
+ return token_type::value_string;
+ }
+basic_json_parser_36:
+ ++m_cursor;
+ if (m_limit <= m_cursor)
+ {
+ yyfill(); // LCOV_EXCL_LINE;
+ }
+ yych = *m_cursor;
+ if (yych <= '@')
+ {
+ if (yych <= '/')
+ {
+ goto basic_json_parser_32;
+ }
+ if (yych >= ':')
+ {
+ goto basic_json_parser_32;
+ }
+ }
+ else
+ {
+ if (yych <= 'F')
+ {
+ goto basic_json_parser_37;
+ }
+ if (yych <= '`')
+ {
+ goto basic_json_parser_32;
+ }
+ if (yych >= 'g')
+ {
+ goto basic_json_parser_32;
+ }
+ }
+basic_json_parser_37:
+ ++m_cursor;
+ if (m_limit <= m_cursor)
+ {
+ yyfill(); // LCOV_EXCL_LINE;
+ }
+ yych = *m_cursor;
+ if (yych <= '@')
+ {
+ if (yych <= '/')
+ {
+ goto basic_json_parser_32;
+ }
+ if (yych >= ':')
+ {
+ goto basic_json_parser_32;
+ }
+ }
+ else
+ {
+ if (yych <= 'F')
+ {
+ goto basic_json_parser_38;
+ }
+ if (yych <= '`')
+ {
+ goto basic_json_parser_32;
+ }
+ if (yych >= 'g')
+ {
+ goto basic_json_parser_32;
+ }
+ }
+basic_json_parser_38:
+ ++m_cursor;
+ if (m_limit <= m_cursor)
+ {
+ yyfill(); // LCOV_EXCL_LINE;
+ }
+ yych = *m_cursor;
+ if (yych <= '@')
+ {
+ if (yych <= '/')
+ {
+ goto basic_json_parser_32;
+ }
+ if (yych >= ':')
+ {
+ goto basic_json_parser_32;
+ }
+ }
+ else
+ {
+ if (yych <= 'F')
+ {
+ goto basic_json_parser_39;
+ }
+ if (yych <= '`')
+ {
+ goto basic_json_parser_32;
+ }
+ if (yych >= 'g')
+ {
+ goto basic_json_parser_32;
+ }
+ }
+basic_json_parser_39:
+ ++m_cursor;
+ if (m_limit <= m_cursor)
+ {
+ yyfill(); // LCOV_EXCL_LINE;
+ }
+ yych = *m_cursor;
+ if (yych <= '@')
+ {
+ if (yych <= '/')
+ {
+ goto basic_json_parser_32;
+ }
+ if (yych <= '9')
+ {
+ goto basic_json_parser_30;
+ }
+ goto basic_json_parser_32;
+ }
+ else
+ {
+ if (yych <= 'F')
+ {
+ goto basic_json_parser_30;
+ }
+ if (yych <= '`')
+ {
+ goto basic_json_parser_32;
+ }
+ if (yych <= 'f')
+ {
+ goto basic_json_parser_30;
+ }
+ goto basic_json_parser_32;
+ }
+basic_json_parser_40:
+ yyaccept = 1;
+ m_marker = ++m_cursor;
+ if ((m_limit - m_cursor) < 3)
+ {
+ yyfill(); // LCOV_EXCL_LINE;
+ }
+ yych = *m_cursor;
+basic_json_parser_41:
+ if (yybm[0 + yych] & 128)
+ {
+ goto basic_json_parser_40;
+ }
+ if (yych <= 'D')
+ {
+ if (yych != '.')
+ {
+ goto basic_json_parser_24;
+ }
+ }
+ else
+ {
+ if (yych <= 'E')
+ {
+ goto basic_json_parser_43;
+ }
+ if (yych == 'e')
+ {
+ goto basic_json_parser_43;
+ }
+ goto basic_json_parser_24;
+ }
+basic_json_parser_42:
+ yych = *++m_cursor;
+ if (yych <= '/')
+ {
+ goto basic_json_parser_32;
+ }
+ if (yych <= '9')
+ {
+ goto basic_json_parser_47;
+ }
+ goto basic_json_parser_32;
+basic_json_parser_43:
+ yych = *++m_cursor;
+ if (yych <= ',')
+ {
+ if (yych != '+')
+ {
+ goto basic_json_parser_32;
+ }
+ }
+ else
+ {
+ if (yych <= '-')
+ {
+ goto basic_json_parser_44;
+ }
+ if (yych <= '/')
+ {
+ goto basic_json_parser_32;
+ }
+ if (yych <= '9')
+ {
+ goto basic_json_parser_45;
+ }
+ goto basic_json_parser_32;
+ }
+basic_json_parser_44:
+ yych = *++m_cursor;
+ if (yych <= '/')
+ {
+ goto basic_json_parser_32;
+ }
+ if (yych >= ':')
+ {
+ goto basic_json_parser_32;
+ }
+basic_json_parser_45:
+ ++m_cursor;
+ if (m_limit <= m_cursor)
+ {
+ yyfill(); // LCOV_EXCL_LINE;
+ }
+ yych = *m_cursor;
+ if (yych <= '/')
+ {
+ goto basic_json_parser_24;
+ }
+ if (yych <= '9')
+ {
+ goto basic_json_parser_45;
+ }
+ goto basic_json_parser_24;
+basic_json_parser_47:
+ yyaccept = 1;
+ m_marker = ++m_cursor;
+ if ((m_limit - m_cursor) < 3)
+ {
+ yyfill(); // LCOV_EXCL_LINE;
+ }
+ yych = *m_cursor;
+ if (yych <= 'D')
+ {
+ if (yych <= '/')
+ {
+ goto basic_json_parser_24;
+ }
+ if (yych <= '9')
+ {
+ goto basic_json_parser_47;
+ }
+ goto basic_json_parser_24;
+ }
+ else
+ {
+ if (yych <= 'E')
+ {
+ goto basic_json_parser_43;
+ }
+ if (yych == 'e')
+ {
+ goto basic_json_parser_43;
+ }
+ goto basic_json_parser_24;
+ }
+basic_json_parser_49:
+ yyaccept = 1;
+ yych = *(m_marker = ++m_cursor);
+ if (yych <= 'D')
+ {
+ if (yych == '.')
+ {
+ goto basic_json_parser_42;
+ }
+ goto basic_json_parser_24;
+ }
+ else
+ {
+ if (yych <= 'E')
+ {
+ goto basic_json_parser_43;
+ }
+ if (yych == 'e')
+ {
+ goto basic_json_parser_43;
+ }
+ goto basic_json_parser_24;
+ }
+basic_json_parser_50:
+ yych = *++m_cursor;
+ if (yych != 'l')
+ {
+ goto basic_json_parser_32;
+ }
+ yych = *++m_cursor;
+ if (yych != 's')
+ {
+ goto basic_json_parser_32;
+ }
+ yych = *++m_cursor;
+ if (yych != 'e')
+ {
+ goto basic_json_parser_32;
+ }
+ ++m_cursor;
+ {
+ return token_type::literal_false;
+ }
+basic_json_parser_55:
+ yych = *++m_cursor;
+ if (yych != 'u')
+ {
+ goto basic_json_parser_32;
+ }
+ yych = *++m_cursor;
+ if (yych != 'e')
+ {
+ goto basic_json_parser_32;
+ }
+ ++m_cursor;
+ {
+ return token_type::literal_true;
+ }
+basic_json_parser_59:
+ yych = *++m_cursor;
+ if (yych != 'l')
+ {
+ goto basic_json_parser_32;
+ }
+ yych = *++m_cursor;
+ if (yych != 'l')
+ {
+ goto basic_json_parser_32;
+ }
+ ++m_cursor;
+ {
+ return token_type::literal_null;
+ }
+ }
+
+
+ }
+
+ /// append data from the stream to the internal buffer
+ void yyfill() noexcept
+ {
+ if (not m_stream or not * m_stream)
+ {
+ return;
+ }
+
+ const ssize_t offset_start = m_start - m_content;
+ const ssize_t offset_marker = m_marker - m_start;
+ const ssize_t offset_cursor = m_cursor - m_start;
+
+ m_buffer.erase(0, static_cast<size_t>(offset_start));
+ std::string line;
+ std::getline(*m_stream, line);
+ m_buffer += "\n" + line; // add line with newline symbol
+
+ m_content = reinterpret_cast<const lexer_char_t*>(m_buffer.c_str());
+ m_start = m_content;
+ m_marker = m_start + offset_marker;
+ m_cursor = m_start + offset_cursor;
+ m_limit = m_start + m_buffer.size() - 1;
+ }
+
+ /// return string representation of last read token
+ string_t get_token() const noexcept
+ {
+ return string_t(reinterpret_cast<typename string_t::const_pointer>(m_start),
+ static_cast<size_t>(m_cursor - m_start));
+ }
+
+ /*!
+ @brief return string value for string tokens
+
+ The function iterates the characters between the opening and closing
+ quotes of the string value. The complete string is the range
+ [m_start,m_cursor). Consequently, we iterate from m_start+1 to
+ m_cursor-1.
+
+ We differentiate two cases:
+
+ 1. Escaped characters. In this case, a new character is constructed
+ according to the nature of the escape. Some escapes create new
+ characters (e.g., @c "\\n" is replaced by @c "\n"), some are copied
+ as is (e.g., @c "\\\\"). Furthermore, Unicode escapes of the shape
+ @c "\\uxxxx" need special care. In this case, to_unicode takes care
+ of the construction of the values.
+ 2. Unescaped characters are copied as is.
+
+ @return string value of current token without opening and closing quotes
+ @throw std::out_of_range if to_unicode fails
+ */
+ string_t get_string() const
+ {
+ string_t result;
+ result.reserve(static_cast<size_t>(m_cursor - m_start - 2));
+
+ // iterate the result between the quotes
+ for (const lexer_char_t* i = m_start + 1; i < m_cursor - 1; ++i)
+ {
+ // process escaped characters
+ if (*i == '\\')
+ {
+ // read next character
+ ++i;
+
+ switch (*i)
+ {
+ // the default escapes
+ case 't':
+ {
+ result += "\t";
+ break;
+ }
+ case 'b':
+ {
+ result += "\b";
+ break;
+ }
+ case 'f':
+ {
+ result += "\f";
+ break;
+ }
+ case 'n':
+ {
+ result += "\n";
+ break;
+ }
+ case 'r':
+ {
+ result += "\r";
+ break;
+ }
+ case '\\':
+ {
+ result += "\\";
+ break;
+ }
+ case '/':
+ {
+ result += "/";
+ break;
+ }
+ case '"':
+ {
+ result += "\"";
+ break;
+ }
+
+ // unicode
+ case 'u':
+ {
+ // get code xxxx from uxxxx
+ auto codepoint = std::strtoul(std::string(reinterpret_cast<typename string_t::const_pointer>(i + 1),
+ 4).c_str(), nullptr, 16);
+
+ // check if codepoint is a high surrogate
+ if (codepoint >= 0xD800 and codepoint <= 0xDBFF)
+ {
+ // make sure there is a subsequent unicode
+ if ((i + 6 >= m_limit) or * (i + 5) != '\\' or * (i + 6) != 'u')
+ {
+ throw std::invalid_argument("missing low surrogate");
+ }
+
+ // get code yyyy from uxxxx\uyyyy
+ auto codepoint2 = std::strtoul(std::string(reinterpret_cast<typename string_t::const_pointer>
+ (i + 7), 4).c_str(), nullptr, 16);
+ result += to_unicode(codepoint, codepoint2);
+ // skip the next 11 characters (xxxx\uyyyy)
+ i += 11;
+ }
+ else
+ {
+ // add unicode character(s)
+ result += to_unicode(codepoint);
+ // skip the next four characters (xxxx)
+ i += 4;
+ }
+ break;
+ }
+ }
+ }
+ else
+ {
+ // all other characters are just copied to the end of the
+ // string
+ result.append(1, static_cast<typename string_t::value_type>(*i));
+ }
+ }
+
+ return result;
+ }
+
+ /*!
+ @brief return number value for number tokens
+
+ This function translates the last token into a floating point number.
+ The pointer m_start points to the beginning of the parsed number. We
+ pass this pointer to std::strtod which sets endptr to the first
+ character past the converted number. If this pointer is not the same as
+ m_cursor, then either more or less characters have been used during the
+ comparison. This can happen for inputs like "01" which will be treated
+ like number 0 followed by number 1.
+
+ @return the result of the number conversion or NAN if the conversion
+ read past the current token. The latter case needs to be treated by the
+ caller function.
+
+ @throw std::range_error if passed value is out of range
+ */
+ long double get_number() const
+ {
+ // conversion
+ typename string_t::value_type* endptr;
+ const auto float_val = std::strtold(reinterpret_cast<typename string_t::const_pointer>(m_start),
+ &endptr);
+
+ // return float_val if the whole number was translated and NAN
+ // otherwise
+ return (reinterpret_cast<lexer_char_t*>(endptr) == m_cursor) ? float_val : NAN;
+ }
+
+ private:
+ /// optional input stream
+ std::istream* m_stream;
+ /// the buffer
+ string_t m_buffer;
+ /// the buffer pointer
+ const lexer_char_t* m_content = nullptr;
+ /// pointer to the beginning of the current symbol
+ const lexer_char_t* m_start = nullptr;
+ /// pointer for backtracking information
+ const lexer_char_t* m_marker = nullptr;
+ /// pointer to the current symbol
+ const lexer_char_t* m_cursor = nullptr;
+ /// pointer to the end of the buffer
+ const lexer_char_t* m_limit = nullptr;
+ };
+
+ /*!
+ @brief syntax analysis
+ */
+ class parser
+ {
+ public:
+ /// constructor for strings
+ parser(const string_t& s, parser_callback_t cb = nullptr)
+ : callback(cb), m_lexer(s)
+ {
+ // read first token
+ get_token();
+ }
+
+ /// a parser reading from an input stream
+ parser(std::istream& _is, parser_callback_t cb = nullptr)
+ : callback(cb), m_lexer(&_is)
+ {
+ // read first token
+ get_token();
+ }
+
+ /// public parser interface
+ basic_json parse()
+ {
+ basic_json result = parse_internal(true);
+
+ expect(lexer::token_type::end_of_input);
+
+ // return parser result and replace it with null in case the
+ // top-level value was discarded by the callback function
+ return result.is_discarded() ? basic_json() : result;
+ }
+
+ private:
+ /// the actual parser
+ basic_json parse_internal(bool keep)
+ {
+ auto result = basic_json(value_t::discarded);
+
+ switch (last_token)
+ {
+ case (lexer::token_type::begin_object):
+ {
+ if (keep and (not callback or (keep = callback(depth++, parse_event_t::object_start, result))))
+ {
+ // explicitly set result to object to cope with {}
+ result.m_type = value_t::object;
+ result.m_value = json_value(value_t::object);
+ }
+
+ // read next token
+ get_token();
+
+ // closing } -> we are done
+ if (last_token == lexer::token_type::end_object)
+ {
+ get_token();
+ if (keep and callback and not callback(--depth, parse_event_t::object_end, result))
+ {
+ result = basic_json(value_t::discarded);
+ }
+ return result;
+ }
+
+ // no comma is expected here
+ unexpect(lexer::token_type::value_separator);
+
+ // otherwise: parse key-value pairs
+ do
+ {
+ // ugly, but could be fixed with loop reorganization
+ if (last_token == lexer::token_type::value_separator)
+ {
+ get_token();
+ }
+
+ // store key
+ expect(lexer::token_type::value_string);
+ const auto key = m_lexer.get_string();
+
+ bool keep_tag = false;
+ if (keep)
+ {
+ if (callback)
+ {
+ basic_json k(key);
+ keep_tag = callback(depth, parse_event_t::key, k);
+ }
+ else
+ {
+ keep_tag = true;
+ }
+ }
+
+ // parse separator (:)
+ get_token();
+ expect(lexer::token_type::name_separator);
+
+ // parse and add value
+ get_token();
+ auto value = parse_internal(keep);
+ if (keep and keep_tag and not value.is_discarded())
+ {
+ result[key] = std::move(value);
+ }
+ }
+ while (last_token == lexer::token_type::value_separator);
+
+ // closing }
+ expect(lexer::token_type::end_object);
+ get_token();
+ if (keep and callback and not callback(--depth, parse_event_t::object_end, result))
+ {
+ result = basic_json(value_t::discarded);
+ }
+
+ return result;
+ }
+
+ case (lexer::token_type::begin_array):
+ {
+ if (keep and (not callback or (keep = callback(depth++, parse_event_t::array_start, result))))
+ {
+ // explicitly set result to object to cope with []
+ result.m_type = value_t::array;
+ result.m_value = json_value(value_t::array);
+ }
+
+ // read next token
+ get_token();
+
+ // closing ] -> we are done
+ if (last_token == lexer::token_type::end_array)
+ {
+ get_token();
+ if (callback and not callback(--depth, parse_event_t::array_end, result))
+ {
+ result = basic_json(value_t::discarded);
+ }
+ return result;
+ }
+
+ // no comma is expected here
+ unexpect(lexer::token_type::value_separator);
+
+ // otherwise: parse values
+ do
+ {
+ // ugly, but could be fixed with loop reorganization
+ if (last_token == lexer::token_type::value_separator)
+ {
+ get_token();
+ }
+
+ // parse value
+ auto value = parse_internal(keep);
+ if (keep and not value.is_discarded())
+ {
+ result.push_back(std::move(value));
+ }
+ }
+ while (last_token == lexer::token_type::value_separator);
+
+ // closing ]
+ expect(lexer::token_type::end_array);
+ get_token();
+ if (keep and callback and not callback(--depth, parse_event_t::array_end, result))
+ {
+ result = basic_json(value_t::discarded);
+ }
+
+ return result;
+ }
+
+ case (lexer::token_type::literal_null):
+ {
+ get_token();
+ result.m_type = value_t::null;
+ break;
+ }
+
+ case (lexer::token_type::value_string):
+ {
+ const auto s = m_lexer.get_string();
+ get_token();
+ result = basic_json(s);
+ break;
+ }
+
+ case (lexer::token_type::literal_true):
+ {
+ get_token();
+ result.m_type = value_t::boolean;
+ result.m_value = true;
+ break;
+ }
+
+ case (lexer::token_type::literal_false):
+ {
+ get_token();
+ result.m_type = value_t::boolean;
+ result.m_value = false;
+ break;
+ }
+
+ case (lexer::token_type::value_number):
+ {
+ auto float_val = m_lexer.get_number();
+
+ // NAN is returned if token could not be translated
+ // completely
+ if (std::isnan(float_val))
+ {
+ throw std::invalid_argument(std::string("parse error - ") +
+ m_lexer.get_token() + " is not a number");
+ }
+
+ get_token();
+
+ // check if conversion loses precision
+ const auto int_val = static_cast<number_integer_t>(float_val);
+ if (approx(float_val, static_cast<long double>(int_val)))
+ {
+ // we basic_json not lose precision -> return int
+ result.m_type = value_t::number_integer;
+ result.m_value = int_val;
+ }
+ else
+ {
+ // we would lose precision -> returnfloat
+ result.m_type = value_t::number_float;
+ result.m_value = static_cast<number_float_t>(float_val);
+ }
+ break;
+ }
+
+ default:
+ {
+ // the last token was unexpected
+ unexpect(last_token);
+ }
+ }
+
+ if (keep and callback and not callback(depth, parse_event_t::value, result))
+ {
+ result = basic_json(value_t::discarded);
+ }
+ return result;
+ }
+
+ /// get next token from lexer
+ typename lexer::token_type get_token()
+ {
+ last_token = m_lexer.scan();
+ return last_token;
+ }
+
+ void expect(typename lexer::token_type t) const
+ {
+ if (t != last_token)
+ {
+ std::string error_msg = "parse error - unexpected \'";
+ error_msg += m_lexer.get_token();
+ error_msg += "\' (" + lexer::token_type_name(last_token);
+ error_msg += "); expected " + lexer::token_type_name(t);
+ throw std::invalid_argument(error_msg);
+ }
+ }
+
+ void unexpect(typename lexer::token_type t) const
+ {
+ if (t == last_token)
+ {
+ std::string error_msg = "parse error - unexpected \'";
+ error_msg += m_lexer.get_token();
+ error_msg += "\' (";
+ error_msg += lexer::token_type_name(last_token) + ")";
+ throw std::invalid_argument(error_msg);
+ }
+ }
+
+ private:
+ /// current level of recursion
+ int depth = 0;
+ /// callback function
+ parser_callback_t callback;
+ /// the type of the last read token
+ typename lexer::token_type last_token = lexer::token_type::uninitialized;
+ /// the lexer
+ lexer m_lexer;
+ };
+};
+
+
+/////////////
+// presets //
+/////////////
+
+/*!
+@brief default JSON class
+
+This type is the default specialization of the @ref basic_json class which uses
+the standard template types.
+*/
+using json = basic_json<>;
+}
+
+
+/////////////////////////
+// nonmember functions //
+/////////////////////////
+
+// specialization of std::swap, and std::hash
+namespace std
+{
+/*!
+@brief exchanges the values of two JSON objects
+*/
+template <>
+inline void swap(nlohmann::json& j1,
+ nlohmann::json& j2) noexcept(
+ is_nothrow_move_constructible<nlohmann::json>::value and
+ is_nothrow_move_assignable<nlohmann::json>::value
+ )
+{
+ j1.swap(j2);
+}
+
+/// hash value for JSON objects
+template <>
+struct hash<nlohmann::json>
+{
+ /// return a hash value for a JSON object
+ std::size_t operator()(const nlohmann::json& j) const
+ {
+ // a naive hashing via the string representation
+ const auto& h = hash<nlohmann::json::string_t>();
+ return h(j.dump());
+ }
+};
+}
+
+/*!
+@brief user-defined string literal for JSON values
+
+This operator implements a user-defined string literal for JSON objects. It can
+be used by adding \p "_json" to a string literal and returns a JSON object if
+no parse error occurred.
+
+@param[in] s a string representation of a JSON object
+@return a JSON object
+*/
+inline nlohmann::json operator "" _json(const char* s, std::size_t)
+{
+ return nlohmann::json::parse(reinterpret_cast<nlohmann::json::string_t::value_type*>
+ (const_cast<char*>(s)));
+}
+
+#endif
--
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