# JSON_HAS_CPP_11, JSON_HAS_CPP_14, JSON_HAS_CPP_17, JSON_HAS_CPP_20 ```cpp #define JSON_HAS_CPP_11 #define JSON_HAS_CPP_14 #define JSON_HAS_CPP_17 #define JSON_HAS_CPP_20 ``` The library targets C++11, but also supports some features introduced in later C++ versions (e.g., `std::string_view` support for C++17). For these new features, the library implements some preprocessor checks to determine the C++ standard. By defining any of these symbols, the internal check is overridden and the provided C++ version is unconditionally assumed. This can be helpful for compilers that only implement parts of the standard and would be detected incorrectly. ## Default definition The default value is detected based on preprocessor macros such as `#!cpp __cplusplus`, `#!cpp _HAS_CXX17`, or `#!cpp _MSVC_LANG`. ## Notes - `#!cpp JSON_HAS_CPP_11` is always defined. - All macros are undefined outside the library. ## Examples ??? example The code below forces the library to use the C++14 standard: ```cpp #define JSON_HAS_CPP_14 1 #include ... ``` ## Version history - Added in version 3.10.5.