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api/macros/json_has_cpp_11/index.md

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+# JSON_HAS_CPP_11, JSON_HAS_CPP_14, JSON_HAS_CPP_17, JSON_HAS_CPP_20, JSON_HAS_CPP_23, JSON_HAS_CPP_26
+
+```
+#define JSON_HAS_CPP_11
+#define JSON_HAS_CPP_14
+#define JSON_HAS_CPP_17
+#define JSON_HAS_CPP_20
+#define JSON_HAS_CPP_23
+#define JSON_HAS_CPP_26
+```
+
+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
+
+- When the C++ standard is detected automatically, `JSON_HAS_CPP_11` is always defined. When you override the detection by defining one of these macros manually, the automatic detection is skipped entirely, so you should define all applicable macros (including `JSON_HAS_CPP_11`) yourself.
+- 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.
+- Added `JSON_HAS_CPP_23` in version 3.12.0.
+- Added `JSON_HAS_CPP_26` in version 3.12.x.