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diff --git a/ext/json/README.md b/ext/json/README.md index 256409e3..f3bbf847 100644 --- a/ext/json/README.md +++ b/ext/json/README.md @@ -5,11 +5,11 @@ [](https://coveralls.io/r/nlohmann/json) [](https://scan.coverity.com/projects/nlohmann-json) [](https://www.codacy.com/app/nlohmann/json?utm_source=github.com&utm_medium=referral&utm_content=nlohmann/json&utm_campaign=Badge_Grade) -[](https://wandbox.org/permlink/Op57X0V7fTf2tdwl) +[](https://wandbox.org/permlink/TarF5pPn9NtHQjhf) [](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) +[](https://github.com/nlohmann/json/releases) +[](http://github.com/nlohmann/json/issues) [](http://isitmaintained.com/project/nlohmann/json "Average time to resolve an issue") [](https://bestpractices.coreinfrastructure.org/projects/289) @@ -21,9 +21,10 @@ - [STL-like access](#stl-like-access) - [Conversion from STL containers](#conversion-from-stl-containers) - [JSON Pointer and JSON Patch](#json-pointer-and-json-patch) + - [JSON Merge Patch](#json-merge-patch) - [Implicit conversions](#implicit-conversions) - [Conversions to/from arbitrary types](#arbitrary-types-conversions) - - [Binary formats (CBOR and MessagePack)](#binary-formats-cbor-and-messagepack) + - [Binary formats (CBOR, MessagePack, and UBJSON)](#binary-formats-cbor-messagepack-and-ubjson) - [Supported compilers](#supported-compilers) - [License](#license) - [Contact](#contact) @@ -39,9 +40,9 @@ There are myriads of [JSON](http://json.org) libraries out there, and each may e - **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'll know what I mean. -- **Trivial integration**. Our whole code consists of a single header file [`json.hpp`](https://github.com/nlohmann/json/blob/develop/src/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. +- **Trivial integration**. Our whole code consists of a single header file [`json.hpp`](https://github.com/nlohmann/json/blob/develop/single_include/nlohmann/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/src/unit.cpp) 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. To maintain high quality, the project is following the [Core Infrastructure Initiative (CII) best practices](https://bestpractices.coreinfrastructure.org/projects/289). +- **Serious testing**. Our class is heavily [unit-tested](https://github.com/nlohmann/json/tree/develop/test/src) and covers [100%](https://coveralls.io/r/nlohmann/json) of the code, including all exceptional behavior. Furthermore, we checked with [Valgrind](http://valgrind.org) and the [Clang Sanitizers](https://clang.llvm.org/docs/index.html) that there are no memory leaks. [Google OSS-Fuzz](https://github.com/google/oss-fuzz/tree/master/projects/json) additionally runs fuzz tests agains all parsers 24/7, effectively executing billions of tests so far. To maintain high quality, the project is following the [Core Infrastructure Initiative (CII) best practices](https://bestpractices.coreinfrastructure.org/projects/289). Other aspects were not so important to us: @@ -54,31 +55,42 @@ See the [contribution guidelines](https://github.com/nlohmann/json/blob/master/. ## 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 +[`json.hpp`](https://github.com/nlohmann/json/blob/develop/single_include/nlohmann/json.hpp) is the single required file in `single_include/nlohmann` or [released here](https://github.com/nlohmann/json/releases). You need to add ```cpp -#include "json.hpp" +#include <nlohmann/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). +to the files you want to process JSON and set the necessary switches to enable C++11 (e.g., `-std=c++11` for GCC and Clang). + +You can further use file [`include/nlohmann/json_fwd.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/json_fwd.hpp) for forward-declarations. The installation of json_fwd.hpp (as part of cmake's install step), can be achieved by setting `-DJSON_MultipleHeaders=ON`. + +### Package Managers :beer: If you are using OS X and [Homebrew](http://brew.sh), just type `brew tap nlohmann/json` and `brew install nlohmann_json` and you're set. If you want the bleeding edge rather than the latest release, use `brew install nlohmann_json --HEAD`. -If you are using the [Meson Build System](http://mesonbuild.com), then you can wrap this repo as a subproject. +If you are using the [Meson Build System](http://mesonbuild.com), then you can wrap this repository as a subproject. If you are using [Conan](https://www.conan.io/) to manage your dependencies, merely add `jsonformoderncpp/x.y.z@vthiery/stable` to your `conanfile.py`'s requires, where `x.y.z` is the release version you want to use. Please file issues [here](https://github.com/vthiery/conan-jsonformoderncpp/issues) if you experience problems with the packages. +If you are using [Spack](https://www.spack.io/) to manage your dependencies, you can use the `nlohmann_json` package. Please see the [spack project](https://github.com/spack/spack) for any issues regarding the packaging. + If you are using [hunter](https://github.com/ruslo/hunter/) on your project for external dependencies, then you can use the [nlohmann_json package](https://docs.hunter.sh/en/latest/packages/pkg/nlohmann_json.html). Please see the hunter project for any issues regarding the packaging. +If you are using [Buckaroo](https://buckaroo.pm), you can install this library's module with `buckaroo install nlohmann/json`. Please file issues [here](https://github.com/LoopPerfect/buckaroo-recipes/issues/new?title=nlohmann/nlohmann/json). + If you are using [vcpkg](https://github.com/Microsoft/vcpkg/) on your project for external dependencies, then you can use the [nlohmann-json package](https://github.com/Microsoft/vcpkg/tree/master/ports/nlohmann-json). Please see the vcpkg project for any issues regarding the packaging. +If you are using [cget](http://cget.readthedocs.io/en/latest/), you can install the latest development version with `cget install nlohmann/json`. A specific version can be installed with `cget install nlohmann/json@v3.1.0`. Also, the multiple header version can be installed by adding the `-DJSON_MultipleHeaders=ON` flag (i.e., `cget install nlohmann/json -DJSON_MultipleHeaders=ON`). + +If you are using [CocoaPods](https://cocoapods.org), you can use the library by adding pod `"nlohmann_json", '~>3.1.2'` to your podfile (see [an example](https://bitbucket.org/benman/nlohmann_json-cocoapod/src/master/)). Please file issues [here](https://bitbucket.org/benman/nlohmann_json-cocoapod/issues?status=new&status=open). ## Examples -Beside the examples below, you may want to check the [documentation](https://nlohmann.github.io/json/) where each function contains a separate code example (e.g., check out [`emplace()`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a602f275f0359ab181221384989810604.html#a602f275f0359ab181221384989810604)). All [example files](https://github.com/nlohmann/json/tree/develop/doc/examples) can be compiled and executed on their own (e.g., file [emplace.cpp](https://github.com/nlohmann/json/blob/develop/doc/examples/emplace.cpp)). +Beside the examples below, you may want to check the [documentation](https://nlohmann.github.io/json/) where each function contains a separate code example (e.g., check out [`emplace()`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a5338e282d1d02bed389d852dd670d98d.html#a5338e282d1d02bed389d852dd670d98d)). All [example files](https://github.com/nlohmann/json/tree/develop/doc/examples) can be compiled and executed on their own (e.g., file [emplace.cpp](https://github.com/nlohmann/json/blob/develop/doc/examples/emplace.cpp)). ### JSON as first-class data type @@ -103,7 +115,7 @@ Assume you want to create the JSON object } ``` -With the JSON class, you could write: +With this library, you could write: ```cpp // create an empty structure (null) @@ -147,7 +159,7 @@ json j2 = { }; ``` -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: +Note that in all these cases, you never need to "tell" the compiler which JSON value type you want to use. If you want to be explicit or express some edge cases, the functions [`json::array`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_aa80485befaffcadaa39965494e0b4d2e.html#aa80485befaffcadaa39965494e0b4d2e) and [`json::object`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_aa13f7c0615867542ce80337cbcf13ada.html#aa13f7c0615867542ce80337cbcf13ada) will help: ```cpp // a way to express the empty array [] @@ -161,12 +173,11 @@ json empty_object_explicit = json::object(); json array_not_object = json::array({ {"currency", "USD"}, {"value", 42.99} }); ``` - ### Serialization / Deserialization #### To/from strings -You can create an object (deserialization) by appending `_json` to a string literal: +You can create a JSON value (deserialization) by appending `_json` to a string literal: ```cpp // create object from string literal @@ -183,14 +194,14 @@ auto j2 = R"( Note that without appending the `_json` suffix, the passed string literal is not parsed, but just used as JSON string value. That is, `json j = "{ \"happy\": true, \"pi\": 3.141 }"` would just store the string `"{ "happy": true, "pi": 3.141 }"` rather than parsing the actual object. -The above example can also be expressed explicitly using `json::parse()`: +The above example can also be expressed explicitly using [`json::parse()`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_aa9676414f2e36383c4b181fe856aa3c0.html#aa9676414f2e36383c4b181fe856aa3c0): ```cpp // parse explicitly auto j3 = json::parse("{ \"happy\": true, \"pi\": 3.141 }"); ``` -You can also get a string representation (serialize): +You can also get a string representation of a JSON value (serialize): ```cpp // explicit conversion to string @@ -225,8 +236,9 @@ std::cout << cpp_string << " == " << cpp_string2 << " == " << j_string.get<std:: std::cout << j_string << " == " << serialized_string << std::endl; ``` -`.dump()` always returns the serialized value, and `.get<std::string>()` returns the originally stored string value. +[`.dump()`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a5adea76fedba9898d404fef8598aa663.html#a5adea76fedba9898d404fef8598aa663) always returns the serialized value, and [`.get<std::string>()`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a16f9445f7629f634221a42b967cdcd43.html#a16f9445f7629f634221a42b967cdcd43) returns the originally stored string value. +Note the library only supports UTF-8. When you store strings with different encodings in the library, calling [`dump()`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a5adea76fedba9898d404fef8598aa663.html#a5adea76fedba9898d404fef8598aa663) may throw an exception. #### To/from streams (e.g. files, string streams) @@ -261,7 +273,7 @@ Please note that setting the exception bit for `failbit` is inappropriate for th #### Read from iterator range -You can also read JSON from an iterator range; that is, from any container accessible by iterators whose content is stored as contiguous byte sequence, for instance a `std::vector<std::uint8_t>`: +You can also parse JSON from an iterator range; that is, from any container accessible by iterators whose content is stored as contiguous byte sequence, for instance a `std::vector<std::uint8_t>`: ```cpp std::vector<std::uint8_t> v = {'t', 'r', 'u', 'e'}; @@ -275,10 +287,53 @@ std::vector<std::uint8_t> v = {'t', 'r', 'u', 'e'}; json j = json::parse(v); ``` +#### SAX interface + +The library uses a SAX-like interface with the following functions: + +```cpp +// called when null is parsed +bool null(); + +// called when a boolean is parsed; value is passed +bool boolean(bool val); + +// called when a signed or unsigned integer number is parsed; value is passed +bool number_integer(number_integer_t val); +bool number_unsigned(number_unsigned_t val); + +// called when a floating-point number is parsed; value and original string is passed +bool number_float(number_float_t val, const string_t& s); + +// called when a string is parsed; value is passed and can be safely moved away +bool string(string_t& val); + +// called when an object or array begins or ends, resp. The number of elements is passed (or -1 if not known) +bool start_object(std::size_t elements); +bool end_object(); +bool start_array(std::size_t elements); +bool end_array(); +// called when an object key is parsed; value is passed and can be safely moved away +bool key(string_t& val); + +// called when a parse error occurs; byte position, the last token, and an exception is passed +bool parse_error(std::size_t position, const std::string& last_token, const detail::exception& ex); +``` + +The return value of each function determines whether parsing should proceed. + +To implement your own SAX handler, proceed as follows: + +1. Implement the SAX interface in a class. You can use class `nlohmann::json_sax<json>` as base class, but you can also use any class where the functions described above are implemented and public. +2. Create an object of your SAX interface class, e.g. `my_sax`. +3. Call `bool json::sax_parse(input, &my_sax)`; where the first parameter can be any input like a string or an input stream and the second parameter is a pointer to your SAX interface. + +Note the `sax_parse` function only returns a `bool` indicating the result of the last executed SAX event. It does not return a `json` value - it is up to you to decide what to do with the SAX events. Furthermore, no exceptions are thrown in case of a parse error - it is up to you what to do with the exception object passed to your `parse_error` implementation. Internally, the SAX interface is used for the DOM parser (class `json_sax_dom_parser`) as well as the acceptor (`json_sax_acceptor`), see file [`json_sax.hpp`](https://github.com/nlohmann/json/blob/develop/include/nlohmann/detail/input/json_sax.hpp). + ### 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. +We designed the JSON class to behave just like an STL container. In fact, it satisfies the [**ReversibleContainer**](https://en.cppreference.com/w/cpp/named_req/ReversibleContainer) requirement. ```cpp // create an array using push_back @@ -352,7 +407,7 @@ 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 on how the elements are ordered in the respective STL container. +Any sequence container (`std::array`, `std::vector`, `std::deque`, `std::forward_list`, `std::list`) whose values can be used to construct JSON values (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 on how the elements are ordered in the respective STL container. ```cpp std::vector<int> c_vector {1, 2, 3, 4}; @@ -392,7 +447,7 @@ 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 can construct an `std::string` and whose values can be used to construct JSON types (see examples above) can be used 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. +Likewise, any associative key-value containers (`std::map`, `std::multimap`, `std::unordered_map`, `std::unordered_multimap`) whose keys can construct an `std::string` and whose values can be used to construct JSON values (see examples above) can be used 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} }; @@ -450,6 +505,37 @@ json::diff(j_result, j_original); // ] ``` +### JSON Merge Patch + +The library supports **JSON Merge Patch** ([RFC 7386](https://tools.ietf.org/html/rfc7386)) as a patch format. Instead of using JSON Pointer (see above) to specify values to be manipulated, it describes the changes using a syntax that closely mimics the document being modified. + +```cpp +// a JSON value +json j_document = R"({ + "a": "b", + "c": { + "d": "e", + "f": "g" + } +})"_json; + +// a patch +json j_patch = R"({ + "a":"z", + "c": { + "f": null + } +})"_json; + +// apply the patch +j_original.merge_patch(j_patch); +// { +// "a": "z", +// "c": { +// "d": "e" +// } +// } +``` ### Implicit conversions @@ -484,9 +570,17 @@ int vi = jn.get<int>(); // etc. ``` +Note that `char` types are not automatically converted to JSON strings, but to integer numbers. A conversion to a string must be specified explicitly: + +```cpp +char ch = 'A'; // ASCII value 65 +json j_default = ch; // stores integer number 65 +json j_string = std::string(1, ch); // stores string "A" +``` + ### Arbitrary types conversions -Every type can be serialized in JSON, not just STL-containers and scalar types. Usually, you would do something along those lines: +Every type can be serialized in JSON, not just STL containers and scalar types. Usually, you would do something along those lines: ```cpp namespace ns { @@ -561,7 +655,8 @@ Likewise, when calling `get<your_type>()`, the `from_json` method will be called Some important things: * Those methods **MUST** be in your type's namespace (which can be the global namespace), or the library will not be able to locate them (in this example, they are in namespace `ns`, where `person` is defined). -* When using `get<your_type>()`, `your_type` **MUST** be [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible). (There is a way to bypass this requirement described later.) +* Those methods **MUST** be available (e.g., properly headers must be included) everywhere you use the implicit conversions. Look at [issue 1108](https://github.com/nlohmann/json/issues/1108) for errors that may occur otherwise. +* When using `get<your_type>()`, `your_type` **MUST** be [DefaultConstructible](https://en.cppreference.com/w/cpp/named_req/DefaultConstructible). (There is a way to bypass this requirement described later.) * In function `from_json`, use function [`at()`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a93403e803947b86f4da2d1fb3345cf2c.html#a93403e803947b86f4da2d1fb3345cf2c) to access the object values rather than `operator[]`. In case a key does not exist, `at` throws an exception that you can handle, whereas `operator[]` exhibits undefined behavior. * In case your type contains several `operator=` definitions, code like `your_variable = your_json;` [may not compile](https://github.com/nlohmann/json/issues/667). You need to write `your_variable = your_json.get<decltype your_variable>();` instead. * You do not need to add serializers or deserializers for STL types like `std::vector`: the library already implements these. @@ -573,7 +668,7 @@ Some important things: This requires a bit more advanced technique. But first, let's see how this conversion mechanism works: The library uses **JSON Serializers** to convert types to json. -The default serializer for `nlohmann::json` is `nlohmann::adl_serializer` (ADL means [Argument-Dependent Lookup](http://en.cppreference.com/w/cpp/language/adl)). +The default serializer for `nlohmann::json` is `nlohmann::adl_serializer` (ADL means [Argument-Dependent Lookup](https://en.cppreference.com/w/cpp/language/adl)). It is implemented like this (simplified): @@ -590,7 +685,7 @@ struct adl_serializer { }; ``` -This serializer works fine when you have control over the type's namespace. However, what about `boost::optional`, or `std::filesystem::path` (C++17)? Hijacking the `boost` namespace is pretty bad, and it's illegal to add something other than template specializations to `std`... +This serializer works fine when you have control over the type's namespace. However, what about `boost::optional` or `std::filesystem::path` (C++17)? Hijacking the `boost` namespace is pretty bad, and it's illegal to add something other than template specializations to `std`... To solve this, you need to add a specialization of `adl_serializer` to the `nlohmann` namespace, here's an example: @@ -612,7 +707,7 @@ namespace nlohmann { if (j.is_null()) { opt = boost::none; } else { - opt = j.get<T>(); // same as above, but with + opt = j.get<T>(); // same as above, but with // adl_serializer<T>::from_json } } @@ -622,7 +717,7 @@ namespace nlohmann { #### How can I use `get()` for non-default constructible/non-copyable types? -There is a way, if your type is [MoveConstructible](http://en.cppreference.com/w/cpp/concept/MoveConstructible). You will need to specialize the `adl_serializer` as well, but with a special `from_json` overload: +There is a way, if your type is [MoveConstructible](https://en.cppreference.com/w/cpp/named_req/MoveConstructible). You will need to specialize the `adl_serializer` as well, but with a special `from_json` overload: ```cpp struct move_only_type { @@ -630,7 +725,7 @@ struct move_only_type { move_only_type(int ii): i(ii) {} move_only_type(const move_only_type&) = delete; move_only_type(move_only_type&&) = default; - + int i; }; @@ -642,7 +737,7 @@ namespace nlohmann { static move_only_type from_json(const json& j) { return {j.get<int>()}; } - + // Here's the catch! You must provide a to_json method! Otherwise you // will not be able to convert move_only_type to json, since you fully // specialized adl_serializer on that type @@ -659,9 +754,9 @@ Yes. You might want to take a look at [`unit-udt.cpp`](https://github.com/nlohma If you write your own serializer, you'll need to do a few things: -* use a different `basic_json` alias than `nlohmann::json` (the last template parameter of `basic_json` is the `JSONSerializer`) -* use your `basic_json` alias (or a template parameter) in all your `to_json`/`from_json` methods -* use `nlohmann::to_json` and `nlohmann::from_json` when you need ADL +- use a different `basic_json` alias than `nlohmann::json` (the last template parameter of `basic_json` is the `JSONSerializer`) +- use your `basic_json` alias (or a template parameter) in all your `to_json`/`from_json` methods +- use `nlohmann::to_json` and `nlohmann::from_json` when you need ADL Here is an example, without simplifications, that only accepts types with a size <= 32, and uses ADL. @@ -677,7 +772,7 @@ struct less_than_32_serializer { // this is where the magic happens to_json(j, value); } - + template <typename BasicJsonType> static void from_json(const BasicJsonType& j, T& value) { // same thing here @@ -699,7 +794,7 @@ struct bad_serializer // if BasicJsonType::json_serializer == bad_serializer ... oops! j = value; } - + template <typename BasicJsonType> static void to_json(const BasicJsonType& j, T& value) { // this calls BasicJsonType::json_serializer<T>::from_json(j, value); @@ -709,9 +804,9 @@ struct bad_serializer }; ``` -### Binary formats (CBOR and MessagePack) +### Binary formats (CBOR, MessagePack, and UBJSON) -Though JSON is a ubiquitous data format, it is not a very compact format suitable for data exchange, for instance over a network. Hence, the library supports [CBOR](http://cbor.io) (Concise Binary Object Representation) and [MessagePack](http://msgpack.org) to efficiently encode JSON values to byte vectors and to decode such vectors. +Though JSON is a ubiquitous data format, it is not a very compact format suitable for data exchange, for instance over a network. Hence, the library supports [CBOR](http://cbor.io) (Concise Binary Object Representation), [MessagePack](http://msgpack.org), and [UBJSON](http://ubjson.org) (Universal Binary JSON Specification) to efficiently encode JSON values to byte vectors and to decode such vectors. ```cpp // create a JSON value @@ -720,7 +815,7 @@ json j = R"({"compact": true, "schema": 0})"_json; // serialize to CBOR std::vector<std::uint8_t> v_cbor = json::to_cbor(j); -// 0xa2, 0x67, 0x63, 0x6f, 0x6d, 0x70, 0x61, 0x63, 0x74, 0xf5, 0x66, 0x73, 0x63, 0x68, 0x65, 0x6d, 0x61, 0x00 +// 0xA2, 0x67, 0x63, 0x6F, 0x6D, 0x70, 0x61, 0x63, 0x74, 0xF5, 0x66, 0x73, 0x63, 0x68, 0x65, 0x6D, 0x61, 0x00 // roundtrip json j_from_cbor = json::from_cbor(v_cbor); @@ -728,19 +823,27 @@ json j_from_cbor = json::from_cbor(v_cbor); // serialize to MessagePack std::vector<std::uint8_t> v_msgpack = json::to_msgpack(j); -// 0x82, 0xa7, 0x63, 0x6f, 0x6d, 0x70, 0x61, 0x63, 0x74, 0xc3, 0xa6, 0x73, 0x63, 0x68, 0x65, 0x6d, 0x61, 0x00 +// 0x82, 0xA7, 0x63, 0x6F, 0x6D, 0x70, 0x61, 0x63, 0x74, 0xC3, 0xA6, 0x73, 0x63, 0x68, 0x65, 0x6D, 0x61, 0x00 // roundtrip json j_from_msgpack = json::from_msgpack(v_msgpack); + +// serialize to UBJSON +std::vector<std::uint8_t> v_ubjson = json::to_ubjson(j); + +// 0x7B, 0x69, 0x07, 0x63, 0x6F, 0x6D, 0x70, 0x61, 0x63, 0x74, 0x54, 0x69, 0x06, 0x73, 0x63, 0x68, 0x65, 0x6D, 0x61, 0x69, 0x00, 0x7D + +// roundtrip +json j_from_ubjson = json::from_ubjson(v_ubjson); ``` ## Supported compilers -Though it's 2017 already, the support for C++11 is still a bit sparse. Currently, the following compilers are known to work: +Though it's 2018 already, the support for C++11 is still a bit sparse. Currently, the following compilers are known to work: -- GCC 4.9 - 7.2 (and possibly later) -- Clang 3.4 - 5.0 (and possibly later) +- GCC 4.9 - 8.2 (and possibly later) +- Clang 3.4 - 6.1 (and possibly later) - Intel C++ Compiler 17.0.2 (and possibly later) - Microsoft Visual C++ 2015 / Build Tools 14.0.25123.0 (and possibly later) - Microsoft Visual C++ 2017 / Build Tools 15.5.180.51428 (and possibly later) @@ -751,43 +854,49 @@ Please note: - GCC 4.8 does not work because of two bugs ([55817](https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55817) and [57824](https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57824)) in the C++11 support. Note there is a [pull request](https://github.com/nlohmann/json/pull/212) to fix some of the issues. - Android defaults to using very old compilers and C++ libraries. To fix this, add the following to your `Application.mk`. This will switch to the LLVM C++ library, the Clang compiler, and enable C++11 and other features disabled by default. - + ``` APP_STL := c++_shared NDK_TOOLCHAIN_VERSION := clang3.6 APP_CPPFLAGS += -frtti -fexceptions ``` - + The code compiles successfully with [Android NDK](https://developer.android.com/ndk/index.html?hl=ml), Revision 9 - 11 (and possibly later) and [CrystaX's Android NDK](https://www.crystax.net/en/android/ndk) version 10. - For GCC running on MinGW or Android SDK, the error `'to_string' is not a member of 'std'` (or similarly, for `strtod`) may occur. Note this is not an issue with the code, but rather with the compiler itself. On Android, see above to build with a newer environment. For MinGW, please refer to [this site](http://tehsausage.com/mingw-to-string) and [this discussion](https://github.com/nlohmann/json/issues/136) for information on how to fix this bug. For Android NDK using `APP_STL := gnustl_static`, please refer to [this discussion](https://github.com/nlohmann/json/issues/219). +- Unsupported versions of GCC and Clang are rejected by `#error` directives. This can be switched off by defining `JSON_SKIP_UNSUPPORTED_COMPILER_CHECK`. Note that you can expect no support in this case. + The following compilers are currently used in continuous integration at [Travis](https://travis-ci.org/nlohmann/json) and [AppVeyor](https://ci.appveyor.com/project/nlohmann/json): | Compiler | Operating System | Version String | |-----------------|------------------------------|----------------| -| GCC 4.9.4 | Ubuntu 14.04.5 LTS | g++-4.9 (Ubuntu 4.9.4-2ubuntu1~14.04.1) 4.9.4 | -| GCC 5.4.1 | Ubuntu 14.04.5 LTS | g++-5 (Ubuntu 5.4.1-2ubuntu1~14.04) 5.4.1 20160904 | -| GCC 6.3.0 | Ubuntu 14.04.5 LTS | g++-6 (Ubuntu/Linaro 6.3.0-18ubuntu2~14.04) 6.3.0 20170519 | -| GCC 7.1.0 | Ubuntu 14.04.5 LTS | g++-7 (Ubuntu 7.1.0-5ubuntu2~14.04) 7.1.0 -| Clang 3.5.0 | Ubuntu 14.04.5 LTS | clang version 3.5.0-4ubuntu2~trusty2 (tags/RELEASE_350/final) | -| Clang 3.6.2 | Ubuntu 14.04.5 LTS | clang version 3.6.2-svn240577-1~exp1 (branches/release_36) | -| Clang 3.7.1 | Ubuntu 14.04.5 LTS | clang version 3.7.1-svn253571-1~exp1 (branches/release_37) | -| Clang 3.8.0 | Ubuntu 14.04.5 LTS | clang version 3.8.0-2ubuntu3~trusty5 (tags/RELEASE_380/final) | -| Clang 3.9.1 | Ubuntu 14.04.5 LTS | clang version 3.9.1-4ubuntu3~14.04.2 (tags/RELEASE_391/rc2) | -| Clang 4.0.1 | Ubuntu 14.04.5 LTS | clang version 4.0.1-svn305264-1~exp1 (branches/release_40) | -| Clang 5.0.0 | Ubuntu 14.04.5 LTS | clang version 5.0.0-svn310902-1~exp1 (branches/release_50) | -| Clang Xcode 6.4 | Darwin Kernel Version 14.3.0 (OSX 10.10.3) | Apple LLVM version 6.1.0 (clang-602.0.53) (based on LLVM 3.6.0svn) | -| Clang Xcode 7.3 | Darwin Kernel Version 15.0.0 (OSX 10.10.5) | Apple LLVM version 7.3.0 (clang-703.0.29) | -| Clang Xcode 8.0 | Darwin Kernel Version 15.6.0 | Apple LLVM version 8.0.0 (clang-800.0.38) | -| Clang Xcode 8.1 | Darwin Kernel Version 16.1.0 (macOS 10.12.1) | Apple LLVM version 8.0.0 (clang-800.0.42.1) | -| Clang Xcode 8.2 | Darwin Kernel Version 16.1.0 (macOS 10.12.1) | Apple LLVM version 8.0.0 (clang-800.0.42.1) | -| Clang Xcode 8.3 | Darwin Kernel Version 16.5.0 (macOS 10.12.4) | Apple LLVM version 8.1.0 (clang-802.0.38) | -| Clang Xcode 9.0 | Darwin Kernel Version 16.7.0 (macOS 10.12.6) | Apple LLVM version 9.0.0 (clang-900.0.37) | -| Clang Xcode 9.1 | Darwin Kernel Version 16.7.0 (macOS 10.12.6) | Apple LLVM version 9.0.0 (clang-900.0.38) | -| Clang Xcode 9.2 | Darwin Kernel Version 16.7.0 (macOS 10.12.6) | Apple LLVM version 8.1.0 (clang-900.0.39.2) | -| Visual Studio 14 2015 | Windows Server 2012 R2 (x64) | Microsoft (R) Build Engine version 14.0.25420.1, MSVC 19.0.24215.1 | -| Visual Studio 2017 | Windows Server 2016 | Microsoft (R) Build Engine version 15.5.180.51428, MSVC 19.12.25830.2 | +| GCC 4.9.4 | Ubuntu 14.04.1 LTS | g++-4.9 (Ubuntu 4.9.4-2ubuntu1~14.04.1) 4.9.4 | +| GCC 5.5.0 | Ubuntu 14.04.1 LTS | g++-5 (Ubuntu 5.5.0-12ubuntu1~14.04) 5.5.0 20171010 | +| GCC 6.4.0 | Ubuntu 14.04.1 LTS | g++-6 (Ubuntu 6.4.0-17ubuntu1~14.04) 6.4.0 20180424 | +| GCC 7.3.0 | Ubuntu 14.04.1 LTS | g++-7 (Ubuntu 7.3.0-21ubuntu1~14.04) 7.3.0 | +| GCC 7.3.0 | Windows Server 2012 R2 (x64) | g++ (x86_64-posix-seh-rev0, Built by MinGW-W64 project) 7.3.0 | +| GCC 8.1.0 | Ubuntu 14.04.1 LTS | g++-8 (Ubuntu 8.1.0-5ubuntu1~14.04) 8.1.0 | +| Clang 3.5.0 | Ubuntu 14.04.1 LTS | clang version 3.5.0-4ubuntu2~trusty2 (tags/RELEASE_350/final) (based on LLVM 3.5.0) | +| Clang 3.6.2 | Ubuntu 14.04.1 LTS | clang version 3.6.2-svn240577-1~exp1 (branches/release_36) (based on LLVM 3.6.2) | +| Clang 3.7.1 | Ubuntu 14.04.1 LTS | clang version 3.7.1-svn253571-1~exp1 (branches/release_37) (based on LLVM 3.7.1) | +| Clang 3.8.0 | Ubuntu 14.04.1 LTS | clang version 3.8.0-2ubuntu3~trusty5 (tags/RELEASE_380/final) | +| Clang 3.9.1 | Ubuntu 14.04.1 LTS | clang version 3.9.1-4ubuntu3~14.04.3 (tags/RELEASE_391/rc2) | +| Clang 4.0.1 | Ubuntu 14.04.1 LTS | clang version 4.0.1-svn305264-1~exp1 (branches/release_40) | +| Clang 5.0.2 | Ubuntu 14.04.1 LTS | clang version 5.0.2-svn328729-1~exp1~20180509123505.100 (branches/release_50) | +| Clang 6.0.1 | Ubuntu 14.04.1 LTS | clang version 6.0.1-svn334776-1~exp1~20180726133705.85 (branches/release_60) | +| Clang Xcode 6.4 | OSX 10.10.5 | Apple LLVM version 6.1.0 (clang-602.0.53) (based on LLVM 3.6.0svn) | +| Clang Xcode 7.3 | OSX 10.11.6 | Apple LLVM version 7.3.0 (clang-703.0.31) | +| Clang Xcode 8.0 | OSX 10.11.6 | Apple LLVM version 8.0.0 (clang-800.0.38) | +| Clang Xcode 8.1 | OSX 10.12.6 | Apple LLVM version 8.0.0 (clang-800.0.42.1) | +| Clang Xcode 8.2 | OSX 10.12.6 | Apple LLVM version 8.0.0 (clang-800.0.42.1) | +| Clang Xcode 8.3 | OSX 10.11.6 | Apple LLVM version 8.1.0 (clang-802.0.38) | +| Clang Xcode 9.0 | OSX 10.12.6 | Apple LLVM version 9.0.0 (clang-900.0.37) | +| Clang Xcode 9.1 | OSX 10.12.6 | Apple LLVM version 9.0.0 (clang-900.0.38) | +| Clang Xcode 9.2 | OSX 10.13.3 | Apple LLVM version 9.1.0 (clang-902.0.39.1) | +| Clang Xcode 9.3 | OSX 10.13.3 | Apple LLVM version 9.1.0 (clang-902.0.39.2) | +| Visual Studio 14 2015 | Windows Server 2012 R2 (x64) | Microsoft (R) Build Engine version 14.0.25420.1, MSVC 19.0.24215.1 | +| Visual Studio 2017 | Windows Server 2016 | Microsoft (R) Build Engine version 15.7.180.61344, MSVC 19.14.26433.0 | ## License @@ -795,7 +904,7 @@ The following compilers are currently used in continuous integration at [Travis] The class is licensed under the [MIT License](http://opensource.org/licenses/MIT): -Copyright © 2013-2017 [Niels Lohmann](http://nlohmann.me) +Copyright © 2013-2018 [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: @@ -807,12 +916,17 @@ THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR I The class contains the UTF-8 Decoder from Bjoern Hoehrmann which is licensed under the [MIT License](http://opensource.org/licenses/MIT) (see above). Copyright © 2008-2009 [Björn Hoehrmann](http://bjoern.hoehrmann.de/) <bjoern@hoehrmann.de> +The class contains a slightly modified version of the Grisu2 algorithm from Florian Loitsch which is licensed under the [MIT License](http://opensource.org/licenses/MIT) (see above). Copyright © 2009 [Florian Loitsch](http://florian.loitsch.com/) + ## Contact -If you have questions regarding the library, I would like to invite you to [open an issue at Github](https://github.com/nlohmann/json/issues/new). Please describe your request, problem, or question as detailed as possible, and also mention the version of the library you are using as well as the version of your compiler and operating system. Opening an issue at Github allows other users and contributors to this library to collaborate. For instance, I have little experience with MSVC, and most issues in this regard have been solved by a growing community. If you have a look at the [closed issues](https://github.com/nlohmann/json/issues?q=is%3Aissue+is%3Aclosed), you will see that we react quite timely in most cases. +If you have questions regarding the library, I would like to invite you to [open an issue at GitHub](https://github.com/nlohmann/json/issues/new). Please describe your request, problem, or question as detailed as possible, and also mention the version of the library you are using as well as the version of your compiler and operating system. Opening an issue at GitHub allows other users and contributors to this library to collaborate. For instance, I have little experience with MSVC, and most issues in this regard have been solved by a growing community. If you have a look at the [closed issues](https://github.com/nlohmann/json/issues?q=is%3Aissue+is%3Aclosed), you will see that we react quite timely in most cases. Only if your request would contain confidential information, please [send me an email](mailto:mail@nlohmann.me). For encrypted messages, please use [this key](https://keybase.io/nlohmann/pgp_keys.asc). +## Security + +[Commits by Niels Lohmann](https://github.com/nlohmann/json/commits) and [releases](https://github.com/nlohmann/json/releases) are signed with this [PGP Key](https://keybase.io/nlohmann/pgp_keys.asc?fingerprint=797167ae41c0a6d9232e48457f3cea63ae251b69). ## Thanks @@ -847,7 +961,7 @@ I deeply appreciate the help of the following people. - [Corbin Hughes](https://github.com/nibroc) fixed some typos in the contribution guidelines. - [twelsby](https://github.com/twelsby) fixed the array subscript operator, an issue that failed the MSVC build, and floating-point parsing/dumping. He further added support for unsigned integer numbers and implemented better roundtrip support for parsed numbers. - [Volker Diels-Grabsch](https://github.com/vog) fixed a link in the README file. -- [msm-](https://github.com/msm-) added support for american fuzzy lop. +- [msm-](https://github.com/msm-) added support for American Fuzzy Lop. - [Annihil](https://github.com/Annihil) fixed an example in the README file. - [Themercee](https://github.com/Themercee) noted a wrong URL in the README file. - [Lv Zheng](https://github.com/lv-zheng) fixed a namespace issue with `int64_t` and `uint64_t`. @@ -860,14 +974,14 @@ I deeply appreciate the help of the following people. - [duncanwerner](https://github.com/duncanwerner) found a really embarrassing performance regression in the 2.0.0 release. - [Damien](https://github.com/dtoma) fixed one of the last conversion warnings. - [Thomas Braun](https://github.com/t-b) fixed a warning in a test case. -- [Théo DELRIEU](https://github.com/theodelrieu) patiently and constructively oversaw the long way toward [iterator-range parsing](https://github.com/nlohmann/json/issues/290). He also implemented the magic behind the serialization/deserialization of user-defined types. +- [Théo DELRIEU](https://github.com/theodelrieu) patiently and constructively oversaw the long way toward [iterator-range parsing](https://github.com/nlohmann/json/issues/290). He also implemented the magic behind the serialization/deserialization of user-defined types and split the single header file into smaller chunks. - [Stefan](https://github.com/5tefan) fixed a minor issue in the documentation. - [Vasil Dimov](https://github.com/vasild) fixed the documentation regarding conversions from `std::multiset`. - [ChristophJud](https://github.com/ChristophJud) overworked the CMake files to ease project inclusion. - [Vladimir Petrigo](https://github.com/vpetrigo) made a SFINAE hack more readable and added Visual Studio 17 to the build matrix. - [Denis Andrejew](https://github.com/seeekr) fixed a grammar issue in the README file. - [Pierre-Antoine Lacaze](https://github.com/palacaze) found a subtle bug in the `dump()` function. -- [TurpentineDistillery](https://github.com/TurpentineDistillery) pointed to [`std::locale::classic()`](http://en.cppreference.com/w/cpp/locale/locale/classic) to avoid too much locale joggling, found some nice performance improvements in the parser, improved the benchmarking code, and realized locale-independent number parsing and printing. +- [TurpentineDistillery](https://github.com/TurpentineDistillery) pointed to [`std::locale::classic()`](https://en.cppreference.com/w/cpp/locale/locale/classic) to avoid too much locale joggling, found some nice performance improvements in the parser, improved the benchmarking code, and realized locale-independent number parsing and printing. - [cgzones](https://github.com/cgzones) had an idea how to fix the Coverity scan. - [Jared Grubb](https://github.com/jaredgrubb) silenced a nasty documentation warning. - [Yixin Zhang](https://github.com/qwename) fixed an integer overflow check. @@ -893,7 +1007,7 @@ I deeply appreciate the help of the following people. - [Vincent Thiery](https://github.com/vthiery) maintains a package for the Conan package manager. - [Steffen](https://github.com/koemeet) fixed a potential issue with MSVC and `std::min`. - [Mike Tzou](https://github.com/Chocobo1) fixed some typos. -- [amrcode](https://github.com/amrcode) noted a missleading documentation about comparison of floats. +- [amrcode](https://github.com/amrcode) noted a misleading documentation about comparison of floats. - [Oleg Endo](https://github.com/olegendo) reduced the memory consumption by replacing `<iostream>` with `<iosfwd>`. - [dan-42](https://github.com/dan-42) cleaned up the CMake files to simplify including/reusing of the library. - [Nikita Ofitserov](https://github.com/himikof) allowed for moving values from initializer lists. @@ -910,25 +1024,50 @@ I deeply appreciate the help of the following people. - [Nate Vargas](https://github.com/eld00d) added a Doxygen tag file. - [pvleuven](https://github.com/pvleuven) helped fixing a warning in ICC. - [Pavel](https://github.com/crea7or) helped fixing some warnings in MSVC. -- [Jamie Seward](https://github.com/jseward) avoided unneccessary string copies in `find()` and `count()`. +- [Jamie Seward](https://github.com/jseward) avoided unnecessary string copies in `find()` and `count()`. - [Mitja](https://github.com/Itja) fixed some typos. - [Jorrit Wronski](https://github.com/jowr) updated the Hunter package links. - [Matthias Möller](https://github.com/TinyTinni) added a `.natvis` for the MSVC debug view. - [bogemic](https://github.com/bogemic) fixed some C++17 deprecation warnings. - [Eren Okka](https://github.com/erengy) fixed some MSVC warnings. - +- [abolz](https://github.com/abolz) integrated the Grisu2 algorithm for proper floating-point formatting, allowing more roundtrip checks to succeed. +- [Vadim Evard](https://github.com/Pipeliner) fixed a Markdown issue in the README. +- [zerodefect](https://github.com/zerodefect) fixed a compiler warning. +- [Kert](https://github.com/kaidokert) allowed to template the string type in the serialization and added the possibility to override the exceptional behavior. +- [mark-99](https://github.com/mark-99) helped fixing an ICC error. +- [Patrik Huber](https://github.com/patrikhuber) fixed links in the README file. +- [johnfb](https://github.com/johnfb) found a bug in the implementation of CBOR's indefinite length strings. +- [Paul Fultz II](https://github.com/pfultz2) added a note on the cget package manager. +- [Wilson Lin](https://github.com/wla80) made the integration section of the README more concise. +- [RalfBielig](https://github.com/ralfbielig) detected and fixed a memory leak in the parser callback. +- [agrianius](https://github.com/agrianius) allowed to dump JSON to an alternative string type. +- [Kevin Tonon](https://github.com/ktonon) overworked the C++11 compiler checks in CMake. +- [Axel Huebl](https://github.com/ax3l) simplified a CMake check and added support for the [Spack package manager](https://spack.io). +- [Carlos O'Ryan](https://github.com/coryan) fixed a typo. +- [James Upjohn](https://github.com/jammehcow) fixed a version number in the compilers section. +- [Chuck Atkins](https://github.com/chuckatkins) adjusted the CMake files to the CMake packaging guidelines +- [Jan Schöppach](https://github.com/dns13) fixed a typo. +- [martin-mfg](https://github.com/martin-mfg) fixed a typo. +- [Matthias Möller](https://github.com/TinyTinni) removed the dependency from `std::stringstream`. +- [agrianius](https://github.com/agrianius) added code to use alternative string implementations. +- [Daniel599](https://github.com/Daniel599) allowed to use more algorithms with the `items()` function. +- [Julius Rakow](https://github.com/jrakow) fixed the Meson include directory and fixed the links to [cppreference.com](cppreference.com). +- [Sonu Lohani](https://github.com/sonulohani) fixed the compilation with MSVC 2015 in debug mode. +- [grembo](https://github.com/grembo) fixed the test suite and re-enabled several test cases. +- [Hyeon Kim](https://github.com/simnalamburt) introduced the macro `JSON_INTERNAL_CATCH` to control the exception handling inside the library. +- [thyu](https://github.com/thyu) fixed a compiler warning. Thanks a lot for helping out! Please [let me know](mailto:mail@nlohmann.me) if I forgot someone. ## Used third-party tools -The library itself contains of a single header file licensed under the MIT license. However, it is built, tested, documented, and whatnot using a lot of third-party tools and services. Thanks a lot! +The library itself consists of a single header file licensed under the MIT license. However, it is built, tested, documented, and whatnot using a lot of third-party tools and services. Thanks a lot! +- [**amalgamate.py - Amalgamate C source and header files**](https://github.com/edlund/amalgamate) to create a single header file - [**American fuzzy lop**](http://lcamtuf.coredump.cx/afl/) for fuzz testing - [**AppVeyor**](https://www.appveyor.com) for [continuous integration](https://ci.appveyor.com/project/nlohmann/json) on Windows - [**Artistic Style**](http://astyle.sourceforge.net) for automatic source code identation -- [**benchpress**](https://github.com/sbs-ableton/benchpress) to benchmark the code - [**Catch**](https://github.com/philsquared/Catch) for the unit tests - [**Clang**](http://clang.llvm.org) for compilation with code sanitizers - [**Cmake**](https://cmake.org) for build automation @@ -936,17 +1075,17 @@ The library itself contains of a single header file licensed under the MIT licen - [**Coveralls**](https://coveralls.io) to measure [code coverage](https://coveralls.io/github/nlohmann/json) - [**Coverity Scan**](https://scan.coverity.com) for [static analysis](https://scan.coverity.com/projects/nlohmann-json) - [**cppcheck**](http://cppcheck.sourceforge.net) for static analysis -- [**cxxopts**](https://github.com/jarro2783/cxxopts) to let benchpress parse command-line parameters - [**Doxygen**](http://www.stack.nl/~dimitri/doxygen/) to generate [documentation](https://nlohmann.github.io/json/) - [**git-update-ghpages**](https://github.com/rstacruz/git-update-ghpages) to upload the documentation to gh-pages -- [**Github Changelog Generator**](https://github.com/skywinder/github-changelog-generator) to generate the [ChangeLog](https://github.com/nlohmann/json/blob/develop/ChangeLog.md) +- [**GitHub Changelog Generator**](https://github.com/skywinder/github-changelog-generator) to generate the [ChangeLog](https://github.com/nlohmann/json/blob/develop/ChangeLog.md) +- [**Google Benchmark**](https://github.com/google/benchmark) to implement the benchmarks - [**libFuzzer**](http://llvm.org/docs/LibFuzzer.html) to implement fuzz testing for OSS-Fuzz -- [**OSS-Fuzz**](https://github.com/google/oss-fuzz) for continuous fuzz testing of the library +- [**OSS-Fuzz**](https://github.com/google/oss-fuzz) for continuous fuzz testing of the library ([project repository](https://github.com/google/oss-fuzz/tree/master/projects/json)) - [**Probot**](https://probot.github.io) for automating maintainer tasks such as closing stale issues, requesting missing information, or detecting toxic comments. - [**send_to_wandbox**](https://github.com/nlohmann/json/blob/develop/doc/scripts/send_to_wandbox.py) to send code examples to [Wandbox](http://melpon.org/wandbox) - [**Travis**](https://travis-ci.org) for [continuous integration](https://travis-ci.org/nlohmann/json) on Linux and macOS - [**Valgrind**](http://valgrind.org) to check for correct memory management -- [**Wandbox**](http://melpon.org/wandbox) for [online examples](https://wandbox.org/permlink/Op57X0V7fTf2tdwl) +- [**Wandbox**](http://melpon.org/wandbox) for [online examples](https://wandbox.org/permlink/TarF5pPn9NtHQjhf) ## Projects using JSON for Modern C++ @@ -956,7 +1095,7 @@ The library is currently used in Apple macOS Sierra and iOS 10. I am not sure wh ## Notes -- The code contains numerous debug **assertions** which can be switched off by defining the preprocessor macro `NDEBUG`, see the [documentation of `assert`](http://en.cppreference.com/w/cpp/error/assert). In particular, note [`operator[]`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a2e26bd0b0168abb61f67ad5bcd5b9fa1.html#a2e26bd0b0168abb61f67ad5bcd5b9fa1) implements **unchecked access** for const objects: If the given key is not present, the behavior is undefined (think of a dereferenced null pointer) and yields an [assertion failure](https://github.com/nlohmann/json/issues/289) if assertions are switched on. If you are not sure whether an element in an object exists, use checked access with the [`at()` function](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a674de1ee73e6bf4843fc5dc1351fb726.html#a674de1ee73e6bf4843fc5dc1351fb726). +- The code contains numerous debug **assertions** which can be switched off by defining the preprocessor macro `NDEBUG`, see the [documentation of `assert`](https://en.cppreference.com/w/cpp/error/assert). In particular, note [`operator[]`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a2e26bd0b0168abb61f67ad5bcd5b9fa1.html#a2e26bd0b0168abb61f67ad5bcd5b9fa1) implements **unchecked access** for const objects: If the given key is not present, the behavior is undefined (think of a dereferenced null pointer) and yields an [assertion failure](https://github.com/nlohmann/json/issues/289) if assertions are switched on. If you are not sure whether an element in an object exists, use checked access with the [`at()` function](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a674de1ee73e6bf4843fc5dc1351fb726.html#a674de1ee73e6bf4843fc5dc1351fb726). - As the exact type of a number is not defined in the [JSON specification](http://rfc7159.net/rfc7159), this library tries to choose the best fitting C++ number type automatically. As a result, the type `double` may be used to store numbers which may yield [**floating-point exceptions**](https://github.com/nlohmann/json/issues/181) in certain rare situations if floating-point exceptions have been unmasked in the calling code. These exceptions are not caused by the library and need to be fixed in the calling code, such as by re-masking the exceptions prior to calling library functions. - The library supports **Unicode input** as follows: - Only **UTF-8** encoded input is supported which is the default encoding for JSON according to [RFC 7159](http://rfc7159.net/rfc7159#rfc.section.8.1). |