std::swappable,std::swappable_with(3)

NAME
std::swappable,std::swappable_with - std::swappable,std::swappable_with

Synopsis
   Defined in header <concepts>
   template< class T >
   concept swappable =
       requires(T& a, T& b) { (1) (since C++20)
           ranges::swap(a, b);
       };
   template< class T, class U >
   concept swappable_with =
       std::common_reference_with<T, U> &&
       requires(T&& t, U&& u) {
           ranges::swap(std::forward<T>(t), std::forward<T>(t)); (2) (since C++20)
           ranges::swap(std::forward<U>(u), std::forward<U>(u));
           ranges::swap(std::forward<T>(t), std::forward<U>(u));
           ranges::swap(std::forward<U>(u), std::forward<T>(t));
       };
   The concept swappable<T> specifies that lvalues of type T are swappable.
   The concept swappable_with<T, U> specifies that expressions of the type and value
   category encoded by T and U are swappable with each other. swappable_with<T, U> is
   satisfied only if a call to ranges::swap(t, u) exchanges the value of t and u, that
   is, given distinct objects t2 equal to t and u2 equal to u, after evaluating either
   ranges::swap(t, u) or ranges::swap(u, t), t2 is equal to u and u2 is equal to t.
   Equality preservation
   Expressions declared in requires expressions of the standard library concepts are
   required to be equality-preserving (except where stated otherwise).