Defined in header <utility> | ||
|---|---|---|
| (1) | ||
template< class T1, class T2 >
void swap( std::pair<T1,T2>& x, std::pair<T1,T2>& y )
noexcept(/* see below */);
| (since C++11) (until C++20) | |
template< class T1, class T2 >
constexpr void swap( std::pair<T1,T2>& x, std::pair<T1,T2>& y )
noexcept(/* see below */);
| (since C++20) | |
template< class T1, class T2 >
constexpr void swap( const std::pair<T1,T2>& x, const std::pair<T1,T2>& y )
noexcept(/* see below */);
| (2) | (since C++23) |
Swaps the contents of x and y. Equivalent to x.swap(y).
1) This overload participates in overload resolution only if std::is_swappable_v<first_type> && std::is_swappable_v<second_type> is true. 2) This overload participates in overload resolution only if std::is_swappable_v<const first_type> && std::is_swappable_v<const second_type> is true. | (since C++17) |
| x, y | - | pairs whose contents to swap |
(none).
noexcept specification: noexcept(noexcept(x.swap(y)))#include <iostream>
#include <utility>
int main()
{
auto p1 = std::make_pair(10, 3.14);
auto p2 = std::pair(12, 1.23); // CTAD, since C++17
auto print_p1_p2 = [&](auto msg) {
std::cout << msg
<< "p1 = {" << std::get<0>(p1)
<< ", " << std::get<1>(p1) << "}, "
<< "p2 = {" << std::get<0>(p2)
<< ", " << std::get<1>(p2) << "}\n";
};
print_p1_p2("Before p1.swap(p2): ");
p1.swap(p2);
print_p1_p2("After p1.swap(p2): ");
std::swap(p1, p2);
print_p1_p2("After swap(p1, p2): ");
}Output:
Before p1.swap(p2): p1 = {10, 3.14}, p2 = {12, 1.23}
After p1.swap(p2): p1 = {12, 1.23}, p2 = {10, 3.14}
After swap(p1, p2): p1 = {10, 3.14}, p2 = {12, 1.23}| swaps the values of two objects (function template) |
|
|
(C++11) | specializes the std::swap algorithm (function template) |
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