JSON for Modern C++  3.7.0

◆ operator=()

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>
basic_json& nlohmann::basic_json::operator= ( basic_json  other)
inlinenoexcept

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
[in]othervalue to copy from
Complexity
Linear.
Requirements
This function helps basic_json satisfying the Container requirements:
  • The complexity is linear.
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.
1 #include <iostream>
2 #include <nlohmann/json.hpp>
3 
4 using json = nlohmann::json;
5 
6 int main()
7 {
8  // create JSON values
9  json a = 23;
10  json b = 42;
11 
12  // copy-assign a to b
13  b = a;
14 
15  // serialize the JSON arrays
16  std::cout << a << '\n';
17  std::cout << b << '\n';
18 }
basic_json<> json
default JSON class
Definition: json.hpp:2355

Output (play with this example online):
23
23
The example code above can be translated with
g++ -std=c++11 -Isingle_include doc/examples/basic_json__copyassignment.cpp -o basic_json__copyassignment 
Since
version 1.0.0

Definition at line 16285 of file json.hpp.