std::mem_fun_ref_t, std::mem_fun1_ref_t, std::const_mem_fun_ref_t, std::const_mem_fun1_ref_t

template< class S, class T > class mem_fun_ref_t : public unary_function<T, S> { public:     explicit mem_fun_ref_t(S (T::*p)());     S operator()(T& p) const; };	(1)	(deprecated)
template< class S, class T, class A > class mem_fun1_ref_t : public binary_function<T, A, S> { public:     explicit mem_fun1_ref_t(S (T::*p)(A));     S operator()(T& p, A x) const; };	(2)	(deprecated)
template< class S, class T > class const_mem_fun_ref_t : public unary_function<T, S> { public:     explicit const_mem_fun_ref_t(S (T::*p)() const);     S operator()(const T& p) const; };	(3)	(deprecated)
template< class S, class T, class A > class const_mem_fun1_ref_t : public binary_function<T, A, S> { public:     explicit const_mem_fun1_ref_t(S (T::*p)(A) const);     S operator()(const T& p, A x) const; };	(4)	(deprecated)

Wrapper around a member function pointer.