JSON for Modern C++ 2.1.1
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◆ swap() [1/4]

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< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::swap ( array_t other)
inline

Exchanges the contents of a JSON array 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]otherarray to exchange the contents with
Exceptions
std::domain_errorwhen JSON value is not an array; example: "cannot use swap() with string"
Complexity\n Constant.
Example\n The example below shows how arrays can be swapped with
swap().
1#include <json.hpp>
2
3using json = nlohmann::json;
4
5int main()
6{
7 // create a JSON value
8 json value = {{"array", {1, 2, 3, 4}}};
9
10 // create an array_t
11 json::array_t array = {"Snap", "Crackle", "Pop"};
12
13 // swap the array stored in the JSON value
14 value["array"].swap(array);
15
16 // output the values
17 std::cout << "value = " << value << '\n';
18 std::cout << "array = " << array << '\n';
19}
static basic_json array(std::initializer_list< basic_json > init=std::initializer_list< basic_json >())
explicitly create an array from an initializer list
Definition json.hpp:2165
void swap(reference other) noexcept(std::is_nothrow_move_constructible< value_t >::value and std::is_nothrow_move_assignable< value_t >::value and std::is_nothrow_move_constructible< json_value >::value and std::is_nothrow_move_assignable< json_value >::value)
exchanges the values
Definition json.hpp:5738
ArrayType< basic_json, AllocatorType< basic_json > > array_t
a type for an array
Definition json.hpp:1328
@ value
the parser finished reading a JSON value
a class to store JSON values
Definition json.hpp:1040
basic_json<> json
default JSON class
Definition json.hpp:12369

Output (play with this example online):
value = {"array":["Snap","Crackle","Pop"]}
array = [1,2,3,4]

The example code above can be translated with
g++ -std=c++11 -Isrc doc/examples/swap__array_t.cpp -o swap__array_t 
Since
version 1.0.0

Definition at line 5770 of file json.hpp.