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#define NLOHMANN_JSON_NAMESPACE /* value */

This macro evaluates to the full name of the nlohmann namespace.

Default definition

The default value consists of the root namespace (nlohmann) and an inline ABI namespace. See nlohmann Namespace for details.

When the macro is not defined, the library will define it to its default value. Overriding this value has no effect on the library.



The example shows how to use NLOHMANN_JSON_NAMESPACE instead of just nlohmann, as well as how to output the value of NLOHMANN_JSON_NAMESPACE.

#include <iostream>
#include <nlohmann/json.hpp>

// possible use case: use NLOHMANN_JSON_NAMESPACE instead of nlohmann
using json = NLOHMANN_JSON_NAMESPACE::json;

// macro needed to output the NLOHMANN_JSON_NAMESPACE as string literal
#define Q(x) #x
#define QUOTE(x) Q(x)

int main()
    std::cout << QUOTE(NLOHMANN_JSON_NAMESPACE) << std::endl;



See also

Version history

  • Added in version 3.11.0. Changed inline namespace name in version 3.11.2.

Last update: August 10, 2022