Defined in header
template< class I1, class I2 = I1 >
concept indirectly_swappable =
indirectly_swappable specifies a relationship between two types respectively modelling std::indirectly_readable, where their referenced types can be swapped.
 Semantic requirements
indirectly_swappable only if all concepts it subsumes are modeled.
 Equality preservation
Expressions declared in requires-expressions of the standard library concepts are required to be equality-preserving (except where stated otherwise).
 See also
| specifies that a type is indirectly readable by applying operator |
| swaps the values referenced by two dereferenceable objects |
(customization point object)