JSON for Modern C++  3.7.2

◆ swap() [3/4]

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 = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
void nlohmann::basic_json::swap ( reference  other)
inlinenoexcept

Exchanges the contents of the JSON value with those of other. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated.

Parameters
[in,out]otherJSON value to exchange the contents with
Complexity
Constant.
Example
The example below shows how JSON values can be swapped with swap().
1 #include <iostream>
2 #include <nlohmann/json.hpp>
3 
4 using json = nlohmann::json;
5 
6 int main()
7 {
8  // create two JSON values
9  json j1 = {1, 2, 3, 4, 5};
10  json j2 = {{"pi", 3.141592653589793}, {"e", 2.718281828459045}};
11 
12  // swap the values
13  j1.swap(j2);
14 
15  // output the values
16  std::cout << "j1 = " << j1 << '\n';
17  std::cout << "j2 = " << j2 << '\n';
18 }

Output (play with this example online):
j1 = {"e":2.718281828459045,"pi":3.141592653589793}
j2 = [1,2,3,4,5]
The example code above can be translated with
g++ -std=c++11 -Isingle_include doc/examples/swap__reference.cpp -o swap__reference 
Since
version 1.0.0

Definition at line 20066 of file json.hpp.

nlohmann::json
basic_json<> json
default JSON class
Definition: json.hpp:2445