const_mem_fun1_t Class

An adapter class that allows a const member function that takes a single argument to be called as a binary function object when initialized with a pointer argument.

template<class Result, class Type, class Arg>
   class const_mem_fun1_t
      : public binary_function<const Type *, Arg, Result> 
   explicit const_mem_fun1_t( Result ( Type::* _Pm )( Arg ) const );
   Result operator()(
      const Type* _Pleft, 
      Arg _Right
   ) const;


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

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

  • _Right
    The argument that is being given to _Pm.

Return Value

An adaptable binary function.


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)(*Right) const.


The constructor of const_mem_fun1_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.


Header: <functional>

Namespace: std

See Also


Thread Safety in the Standard C++ Library

Standard Template Library

Other Resources

<functional> Members