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JSON_HAS_CPP_11, JSON_HAS_CPP_14, JSON_HAS_CPP_17, JSON_HAS_CPP_20

#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 __cplusplus, _HAS_CXX17, or _MSVC_LANG.

Notes

  • 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:

#define JSON_HAS_CPP_14 1
#include <nlohmann/json.hpp>

...

Version history

  • Added in version 3.10.5.

Last update: October 2, 2022