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;
};

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;
};

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;
};

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;
};