[/ Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.com) Copyright (c) 2020 Krystian Stasiowski (sdkrystian@gmail.com) Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) Official repository: https://github.com/cppalliance/json ] [section Overview] [block''''''] [/-----------------------------------------------------------------------------] Boost.JSON is a portable C++ library which provides containers and algorithms that implement [@https://json.org/ JavaScript Object Notation], or simply "JSON", a lightweight data-interchange format. This format is easy for humans to read and write, and easy for machines to parse and generate. It is based on a subset of the JavaScript Programming Language ([@https://www.ecma-international.org/ecma-262/10.0/index.html Standard ECMA-262]). JSON is a text format that is language-independent but uses conventions that are familiar to programmers of the C-family of languages, including C, C++, C#, Java, JavaScript, Perl, Python, and many others. These properties make JSON an ideal data-interchange language. This library focuses on a common and popular use-case: parsing and serializing to and from a container called __value__ which holds JSON types. Any __value__ which you build can be serialized and then deserialized, guaranteeing that the result will be equal to the original value. Whatever JSON output you produce with this library will be readable by most common JSON implementations in any language. The __value__ container is designed to be well suited as a vocabulary type appropriate for use in public interfaces and libraries, allowing them to be composed. The library restricts the representable data types to the ranges which are almost universally accepted by most JSON implementations, especially JavaScript. The parser and serializer are both highly performant, meeting or exceeding the benchmark performance of the best comparable libraries. Allocators are very well supported. Code which uses these types will be easy to understand, flexible, and performant. Boost.JSON offers these features: * Fast compilation * Require only C++11 * Fast streaming parser and serializer * Constant-time key lookup for objects * Options to allow non-standard JSON * Easy and safe modern API with allocator support * Compile without Boost, define `BOOST_JSON_STANDALONE` * Optional header-only, without linking to a library [/-----------------------------------------------------------------------------] [section Requirements] The library relies heavily on these well known C++ types in its interfaces (henceforth termed ['standard types]): * __string_view__ * __memory_resource__, __polymorphic_allocator__ * __error_category__, __error_code__, __error_condition__, __system_error__ The requirements for Boost.JSON depend on whether the library is used as part of Boost, or in the standalone flavor (without Boost): [heading Using Boost] * Requires only C++11 * The default configuration * Aliases for standard types use their Boost equivalents * Link to a built static or dynamic Boost library, or use header-only (see below) * Supports -fno-exceptions, detected automatically [heading Without Boost] * Requires C++17 * Aliases for standard types use their `std` equivalents * Obtained when defining the macro `BOOST_JSON_STANDALONE` * Link to a built static or dynamic standalone library, or use header-only (see below) * Supports -fno-exceptions: define `BOOST_NO_EXCEPTIONS` and `boost::throw_exception` manually When using without Boost, support for `` is required. In particular, if using libstdc++ then version 8.3 or later is needed. [heading Header-Only] To use as header-only; that is, to eliminate the requirement to link a program to a static or dynamic Boost.JSON library, simply place the following line in exactly one new or existing source file in your project. ``` #include ``` [heading Standalone Shared Library] To build a standalone shared library, it is necessary to define the macros `BOOST_JSON_DECL` and `BOOST_JSON_CLASS_DECL` as appropriate for your toolchain. Example for MSVC: ``` // When building the DLL #define BOOST_JSON_DECL __declspec(dllexport) #define BOOST_JSON_CLASS_DECL __declspec(dllexport) // When building the application which uses the DLL #define BOOST_JSON_DECL __declspec(dllimport) #define BOOST_JSON_CLASS_DECL __declspec(dllimport) ``` [heading Embedded] Boost.JSON works great on embedded devices. The library uses local stack buffers to increase the performance of some operations. On Intel platforms these buffers are large (4KB), while on non-Intel platforms they are small (256 bytes). To adjust the size of the stack buffers for embedded applications define this macro when building the library or including the function definitions: ``` #define BOOST_JSON_STACK_BUFFER_SIZE 1024 #include ``` [note This library uses separate inline namespacing for the standalone mode to allow libraries which use different modes to compose without causing link errors. Linking to both modes of Boost.JSON (Boost and standalone) is possible, but not recommended. ] [endsect] [/-----------------------------------------------------------------------------] [section Supported Compilers] Boost.JSON has been tested with the following compilers: * clang: 3.8, 4, 5, 6, 7, 8, 9, 10, 11 * gcc: 4.8, 4.9, 5, 6, 7, 8, 9, 10 * msvc: 14.0, 14.1, 14.2 [h3 Quality Assurance] The development infrastructure for the library includes these per-commit analyses: * Coverage reports * Benchmark performance comparisons * Compilation and tests on Drone.io, Azure Pipelines, Appveyor * Fuzzing using clang-llvm and machine learning [endsect] [/-----------------------------------------------------------------------------] [section Security Review (Bishop Fox)] As part of our commitment to producing the very finest C++ libraries that application developers can trust, the C++ Alliance has commissioned Bishop Fox to perform a security audit of the Boost.JSON library. The report is linked here: [@https://cppalliance.org/pdf/C%20Plus%20Plus%20Alliance%20-%20Boost%20JSON%20Security%20Assessment%202020%20-%20Assessment%20Report%20-%2020210317.pdf C Plus Plus Alliance - Boost JSON Security Assessment 2020 - Assessment Report - 20210317] [endsect] [/-----------------------------------------------------------------------------] [h1 Credits] This library wouldn't be where it is today without the help of [@https://github.com/pdimov Peter Dimov] for design advice and optimization assistance. [/-----------------------------------------------------------------------------] [endsect]