template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = int64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator>

nlohmann::basic_json::basic_json ( const number_float_t  value )

inline

Create a floating-point number JSON value with a given content.

Parameters

[in]

value

a floating-point value to create a JSON number from

Note

RFC 7159 http://www.rfc-editor.org/rfc/rfc7159.txt, section 6 disallows NaN values:

Numeric values that cannot be represented in the grammar below (such as Infinity and NaN) are not permitted.

In case the parameter value is not a number, a JSON null value is created instead.

Complexity

Constant.

Example

The following example creates several floating-point values.

#include <json.hpp>

using namespace nlohmann;

int main()
{
    // create values of different floating-point types
    json::number_float_t v_ok = 3.141592653589793;
    json::number_float_t v_nan = NAN;
    json::number_float_t v_infinity = INFINITY;

    // create JSON numbers
    json j_ok(v_ok);
    json j_nan(v_nan);
    json j_infinity(v_infinity);

    // serialize the JSON numbers
    std::cout << j_ok << '\n';
    std::cout << j_nan << '\n';
    std::cout << j_infinity << '\n';
}

Output:

3.14159265358979
null
null

The example code above can be translated with

g++ -std=c++11 -Isrc doc/examples/basic_json__number_float_t.cpp -o basic_json__number_float_t 

.