The class templates unary_function and binary_function are deprecated. A program shall not declare specializations of these templates.
namespace std {
template <class Arg, class Result>
struct unary_function {
typedef Arg argument_type;
typedef Result result_type;
};
}
namespace std {
template <class Arg1, class Arg2, class Result>
struct binary_function {
typedef Arg1 first_argument_type;
typedef Arg2 second_argument_type;
typedef Result result_type;
};
}
The adaptors ptr_fun, mem_fun, mem_fun_ref, and their corresponding return types are deprecated. [ Note: The function template bind [func.bind] provides a better solution. — end note ]
To allow pointers to (unary and binary) functions to work with function adaptors the library provides:
template <class Arg, class Result>
class pointer_to_unary_function : public unary_function<Arg, Result> {
public:
explicit pointer_to_unary_function(Result (*f)(Arg));
Result operator()(Arg x) const;
};
operator() returns f(x).
template <class Arg, class Result>
pointer_to_unary_function<Arg, Result> ptr_fun(Result (*f)(Arg));
Returns: pointer_to_unary_function<Arg, Result>(f).
template <class Arg1, class Arg2, class Result>
class pointer_to_binary_function :
public binary_function<Arg1,Arg2,Result> {
public:
explicit pointer_to_binary_function(Result (*f)(Arg1, Arg2));
Result operator()(Arg1 x, Arg2 y) const;
};
operator() returns f(x,y).
template <class Arg1, class Arg2, class Result>
pointer_to_binary_function<Arg1,Arg2,Result>
ptr_fun(Result (*f)(Arg1, Arg2));
Returns: pointer_to_binary_function<Arg1,Arg2,Result>(f).
[ Example:
int compare(const char*, const char*); replace_if(v.begin(), v.end(), not1(bind2nd(ptr_fun(compare), "abc")), "def");
replaces each abc with def in sequence v. — end example ]
The purpose of the following is to provide the same facilities for pointer to members as those provided for pointers to functions in [depr.function.pointer.adaptors].
template <class S, class T> class mem_fun_t
: public unary_function<T*, S> {
public:
explicit mem_fun_t(S (T::*p)());
S operator()(T* p) const;
};
mem_fun_t calls the member function it is initialized with given a pointer argument.
template <class S, class T, class A> class mem_fun1_t
: public binary_function<T*, A, S> {
public:
explicit mem_fun1_t(S (T::*p)(A));
S operator()(T* p, A x) const;
};
mem_fun1_t calls the member function it is initialized with given a pointer argument and an additional argument of the appropriate type.
template<class S, class T> mem_fun_t<S,T>
mem_fun(S (T::*f)());
template<class S, class T, class A> mem_fun1_t<S,T,A>
mem_fun(S (T::*f)(A));
mem_fun(&X::f) returns an object through which X::f can be called given a pointer to an X followed by the argument required for f (if any).
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;
};
mem_fun_ref_t calls the member function it is initialized with given a reference argument.
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;
};
mem_fun1_ref_t calls the member function it is initialized with given a reference argument and an additional argument of the appropriate type.
template<class S, class T> mem_fun_ref_t<S,T>
mem_fun_ref(S (T::*f)());
template<class S, class T, class A> mem_fun1_ref_t<S,T,A>
mem_fun_ref(S (T::*f)(A));
mem_fun_ref(&X::f) returns an object through which X::f can be called given a reference to an X followed by the argument required for f (if any).
template <class S, class T> class const_mem_fun_t
: public unary_function<const T*, S> {
public:
explicit const_mem_fun_t(S (T::*p)() const);
S operator()(const T* p) const;
};
const_mem_fun_t calls the member function it is initialized with given a pointer argument.
template <class S, class T, class A> class const_mem_fun1_t
: public binary_function<const T*, A, S> {
public:
explicit const_mem_fun1_t(S (T::*p)(A) const);
S operator()(const T* p, A x) const;
};
const_mem_fun1_t calls the member function it is initialized with given a pointer argument and an additional argument of the appropriate type.
template<class S, class T> const_mem_fun_t<S,T>
mem_fun(S (T::*f)() const);
template<class S, class T, class A> const_mem_fun1_t<S,T,A>
mem_fun(S (T::*f)(A) const);
mem_fun(&X::f) returns an object through which X::f can be called given a pointer to an X followed by the argument required for f (if any).
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;
};
const_mem_fun_ref_t calls the member function it is initialized with given a reference argument.
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;
};
const_mem_fun1_ref_t calls the member function it is initialized with given a reference argument and an additional argument of the appropriate type.
template<class S, class T> const_mem_fun_ref_t<S,T>
mem_fun_ref(S (T::*f)() const);
template<class S, class T, class A> const_mem_fun1_ref_t<S,T,A>
mem_fun_ref(S (T::*f)(A) const);
mem_fun_ref(&X::f) returns an object through which X::f can be called given a reference to an X followed by the argument required for f (if any).