cpp/experimental/ranges/concepts/Swappable

The concept specifies that lvalues of type  are swappable.

The concept specifies that expressions of the type and value category encoded by  and  are swappable with each other. is satisfied only if a call to exchanges the value of  and, that is, given distinct objects  equal to  and  equal to , after evaluating either  or ,  is equal to  and  is equal to.