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std::swap<basic_json>

namespace std {
    void swap(nlohmann::basic_json& j1, nlohmann::basic_json& j2);
}

Exchanges the values of two JSON objects.

Parameters

j1 (in, out)
value to be replaced by j2
j2 (in, out)
value to be replaced by j1

Possible implementation

void swap(nlohmann::basic_json& j1, nlohmann::basic_json& j2)
{
    j1.swap(j2);
}

Examples

Example

The following code shows how two values are swapped with std::swap.

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

using json = nlohmann::json;

int main()
{
    // create JSON values
    json j1 = {{"one", 1}, {"two", 2}};
    json j2 = {1, 2, 4, 8, 16};

    std::cout << "j1 = " << j1 << " | j2 = " << j2 << '\n';

    // swap values
    std::swap(j1, j2);

    std::cout << "j1 = " << j1 << " | j2 = " << j2 << std::endl;
}

Output:

j1 = {"one":1,"two":2} | j2 = [1,2,4,8,16]
j1 = [1,2,4,8,16] | j2 = {"one":1,"two":2}

See also

Version history

  • Added in version 1.0.0.
  • Extended for arbitrary basic_json types in version 3.10.5.

Last update: May 1, 2022
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