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nlohmann::basic_json::operator=

basic_json& operator=(basic_json other) noexcept (
    std::is_nothrow_move_constructible<value_t>::value &&
    std::is_nothrow_move_assignable<value_t>::value &&
    std::is_nothrow_move_constructible<json_value>::value &&
    std::is_nothrow_move_assignable<json_value>::value
);

Copy assignment operator. Copies a JSON value via the "copy and swap" strategy: It is expressed in terms of the copy constructor, destructor, and the swap() member function.

Parameters

other (in)
value to copy from

Complexity

Linear.

Examples

Example

The code below shows and example for the copy assignment. It creates a copy of value a which is then swapped with b. Finally, the copy of a (which is the null value after the swap) is destroyed.

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

using json = nlohmann::json;

int main()
{
    // create JSON values
    json a = 23;
    json b = 42;

    // copy-assign a to b
    b = a;

    // serialize the JSON arrays
    std::cout << a << '\n';
    std::cout << b << '\n';
}

Output:

23
23

Version history

  • Added in version 1.0.0.
Last update: May 1, 2022