std::swap(std::optional)

Defined in header <optional>
template< class T >
void swap( optional<T>& lhs, optional<T>& rhs ) noexcept(/* see below */);
(since C++17)

Overloads the std::swap algorithm for std::optional. Exchanges the state of lhs with that of rhs. Effectively calls lhs.swap(rhs).

This function template does not participate in overload resolution unless std::is_move_constructible_v<T> and std::is_swappable_v<T> are both true.

Parameters

lhs, rhs - optional objects whose states to swap

Return value

(none).

Exceptions

noexcept specification:
noexcept(noexcept(lhs.swap(rhs)))

Example

See also

exchanges the contents
(public member function)

© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
http://en.cppreference.com/w/cpp/utility/optional/swap2