21 Containers library [containers]

21.6 Container adaptors [container.adaptors]

21.6.6 Class template stack [stack]

21.6.6.5 Specialized algorithms [stack.special]

template<class T, class Container> void swap(stack<T, Container>& x, stack<T, Container>& y) noexcept(noexcept(x.swap(y)));
Remarks: This function shall not participate in overload resolution unless is_­swappable_­v<Container> is true.
Effects: As if by x.swap(y).