cpp/utility/functional/mem fn

Function template generates wrapper objects for pointers to members, which can store, copy, and invoke a pointer to member. Both references and pointers (including smart pointers) to an object can be used when invoking a.

Return value
returns a call wrapper of unspecified type that has the following members:

{{member|{{small|std::mem_fn}} return type|2= {{rrev|until=c++20|

Member types
}}

Member function
The expression is equivalent to, where  is the  object held by , it is of type  and is direct-non-list-initialized with.

Thus, the return type of is.

Each argument in is perfectly forwarded, as if by. }}