const_mem_fun_t Class

An adapter class that allows a const member function that takes no arguments to be called as a unary function object when initialized with a reference argument.

template<class Result, class Type>
   class const_mem_fun_t : public unary_function <Type *, Result> 
   {
   explicit const_mem_fun_t( Result ( Type::* _Pm )( ) const );
   Result operator()(
      const Type* _Pleft
   ) const;
   };

Parameters

• _Pm
  A pointer to the member function of class Type to be converted to a function object.

• _Pleft
  The object that the _Pm member function is called on.

Return Value

An adaptable unary function.

Remarks

The template class stores a copy of _Pm, which must be a pointer to a member function of class Type, in a private member object. It defines its member function operator() as returning (_Pleft->* _Pm)() const.

Example

The constructor of const_mem_fun_t is not usually used directly; the helper function mem_fun is used to adapt member functions. See mem_fun for an example of how to use member function adaptors.

Requirements

Header: <functional>

Namespace: std

See Also

Reference

Thread Safety in the C++ Standard Library

Standard Template Library