c++ STL swap用法和实现

一：功能

      交换两个值

二：用法 

#include <format>
#include <iostream>namespace Library {
struct Storage {int value;
};//支持swap操作
void swap(Storage& left, Storage& right) {std::ranges::swap(left.value, right.value);
}
}int main() {int a = 1, b = 2;std::ranges::swap(a, b); // 3-step-swapstd::format_to(std::ostreambuf_iterator(std::cout),"a == {}, b == {}\n", a, b);Library::Storage j{2}, k{3};std::ranges::swap(j, k); // calls custom Library::swap()std::format_to(std::ostreambuf_iterator(std::cout),"j == {}, k == {}\n", j.value, k.value);
}

三：实现

#include <algorithm>
#include <iostream>template<typename T>
void my_swap(T &a,T &b) noexcept
{T temp = std::move(a);a = std::move(b);b = std::move(temp);
}int main()
{int a = 5, b = 3;std::cout << a << ' ' << b << '\n';my_swap(a, b);std::cout << a << ' ' << b << '\n';
}