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Standard C++ Library
Copyright 1996, Rogue Wave Software, Inc.
NAME
bind1st, bind2nd, binder1st, binder2nd - Templatized utilities to
bind values to function objects
SYNOPSIS
#include <functional>
template <class Operation>
class binder1st : public unary_function<typename
Operation::second_argument_type,
typename Operation::result_type> ;
template <class Operation, class T>
binder1st<Operation> bind1st (const Operation&, const T&);
template <class Operation>
class binder2nd : public unary_function<typename
Operation::first_argument_type,
typename Operation::result_type> ;
template <class Operation, class T>
binder2nd<Operation> bind2nd (const Operation&, const T&);
DESCRIPTION
Because so many functions provided by the standard library take
other functions as arguments, the library includes classes that
let you build new function objects out of old ones. Both
bind1st() and bind2nd() are functions that take as arguments a
binary function object f and a value x, and return, respectively,
classes binder1st and binder2nd. The underlying function object
must be a subclass of binary_function.
Class binder1st binds the value to the first argument of the binary
function, and binder2nd does the same thing for the second
argument of the function. The resulting classes can be used in
place of a unary predicate in other function calls.
For example, you could use the count_if algorithm to count all
elements in a vector that are less than or equal to 7, using the
following:
count_if (v.begin, v.end, bind1st(greater<int> (),7), littleNums)
This function adds one to littleNums each time the predicate is
true, i.e., each time 7 is greater than the element.
INTERFACE
// Class binder1st
template <class Operation>
class binder1st
: public unary_function<typename
Operation::second_argument_type,
typename Operation::result_type>
{
public:
typedef typename unary_function<typename
Operation::second_argument_type, typename
Operation::result_type>::argument_type argument_type;
typedef typename unary_function<typename
Operation::second_argument_type, typename
Operation::result_type>::result_type result_type;
binder1st(const Operation&,
const typename Operation::first_argument_type&);
result_type operator() (const argument_type&) const;
};
// Class binder2nd
template <class Operation>
class binder2nd
: public unary_function<typename
Operation::first_argument_type,
typename Operation::result_type>
{
public:
typedef typename unary_function<typename
Operation::first_argument_type, typename
Operation::result_type>::argument_type argument_type;
typedef typename unary_function<typename
Operation::first_argument_type, typename
Operation::result_type>::result_type result_type;
binder2nd(const Operation&,
const typename Operation::second_argument_type&);
result_type operator() (const argument_type&) const;
};
// Creator bind1st
template <class Operation, class T>
binder1st<Operation> bind1st (const Operation&, const T&);
// Creator bind2nd
template<class Operation, class T>
binder2nd <Operation> bind2nd(const Operation&, const T&);
EXAMPLE
//
// binders.cpp
//
#include <functional>
#include <algorithm>
#include <vector>
#include <iostream.h>
int main()
{
typedef vector<int>::iterator iterator;
int d1[4] = {1,2,3,4};
//
// Set up a vector
//
vector<int> v1(d1,d1 + 4);
//
// Create an 'equal to 3' unary predicate by binding 3 to
// the equal_to binary predicate.
//
binder1st<equal_to<int> > equal_to_3 =
bind1st(equal_to<int>(),3);
//
// Now use this new predicate in a call to find_if
//
iterator it1 = find_if(v1.begin(),v1.end(),equal_to_3);
//
// Even better, construct the new predicate on the fly
//
iterator it2 =
find_if(v1.begin(),v1.end(),bind1st(equal_to<int>(),3));
//
// And now the same thing using bind2nd
// Same result since == is commutative
//
iterator it3 =
find_if(v1.begin(),v1.end(),bind2nd(equal_to<int>(),3));
//
// it3 = v1.begin() + 2
//
// Output results
//
cout << *it1 << " " << *it2 << " " << *it3 << endl;
return 0;
}
Output : 3 3 3
WARNINGS
If your compiler does not support default template parameters then
you need to always supply the Allocator template argument. For
instance you'll have to write:
vector<int,allocator<int> > instead of:
vector<int>
SEE ALSO
Function Object
STANDARDS CONFORMANCE
ANSI X3J16/ISO WG21 Joint C++ Committee
Standard C++ Library
Copyright 1996, Rogue Wave Software, Inc.
NAME
bind1st, bind2nd, binder1st, binder2nd - Templatized utilities to
bind values to function objects
SYNOPSIS
#include <functional>
template <class Operation>
class binder1st : public unary_function<typename
Operation::second_argument_type,
typename Operation::result_type> ;
template <class Operation, class T>
binder1st<Operation> bind1st (const Operation&, const T&);
template <class Operation>
class binder2nd : public unary_function<typename
Operation::first_argument_type,
typename Operation::result_type> ;
template <class Operation, class T>
binder2nd<Operation> bind2nd (const Operation&, const T&);
DESCRIPTION
Because so many functions provided by the standard library take
other functions as arguments, the library includes classes
that let you build new function objects out of old ones. Both
bind1st() and bind2nd() are functions that take as arguments
a binary function object f and a value x, and return,
respectively, classes binder1st and binder2nd. The underlying
function object must be a subclass of binary_function.
Class binder1st binds the value to the first argument of the binary
function, and binder2nd does the same thing for the second
argument of the function. The resulting classes can be used in
place of a unary predicate in other function calls.
For example, you could use the count_if algorithm to count all
elements in a vector that are less than or equal to 7, using the
following:
count_if (v.begin, v.end, bind1st(greater<int> (),7), littleNums)
This function adds one to littleNums each time the predicate is
true, i.e., each time 7 is greater than the element.
INTERFACE
// Class binder1st
template <class Operation>
class binder1st
: public unary_function<typename
Operation::second_argument_type,
typename Operation::result_type>
{
public:
typedef typename unary_function<typename
Operation::second_argument_type, typename
Operation::result_type>::argument_type argument_type;
typedef typename unary_function<typename
Operation::second_argument_type, typename
Operation::result_type>::result_type result_type;
binder1st(const Operation&,
const typename Operation::first_argument_type&);
result_type operator() (const argument_type&) const;
};
// Class binder2nd
template <class Operation>
class binder2nd
: public unary_function<typename
Operation::first_argument_type,
typename Operation::result_type>
{
public:
typedef typename unary_function<typename
Operation::first_argument_type, typename
Operation::result_type>::argument_type argument_type;
typedef typename unary_function<typename
Operation::first_argument_type, typename
Operation::result_type>::result_type result_type;
binder2nd(const Operation&,
const typename Operation::second_argument_type&);
result_type operator() (const argument_type&) const;
};
// Creator bind1st
template <class Operation, class T>
binder1st<Operation> bind1st (const Operation&, const T&);
// Creator bind2nd
template<class Operation, class T>
binder2nd <Operation> bind2nd(const Operation&, const T&);
EXAMPLE
//
// binders.cpp
//
#include <functional>
#include <algorithm>
#include <vector>
#include <iostream.h>
int main()
{
typedef vector<int>::iterator iterator;
int d1[4] = {1,2,3,4};
//
// Set up a vector
//
vector<int> v1(d1,d1 + 4);
//
// Create an 'equal to 3' unary predicate by binding 3 to
// the equal_to binary predicate.
//
binder1st<equal_to<int> > equal_to_3 =
bind1st(equal_to<int>(),3);
//
// Now use this new predicate in a call to find_if
//
iterator it1 = find_if(v1.begin(),v1.end(),equal_to_3);
//
// Even better, construct the new predicate on the fly
//
iterator it2 =
find_if(v1.begin(),v1.end(),bind1st(equal_to<int>(),3));
//
// And now the same thing using bind2nd
// Same result since == is commutative
//
iterator it3 =
find_if(v1.begin(),v1.end(),bind2nd(equal_to<int>(),3));
//
// it3 = v1.begin() + 2
//
// Output results
//
cout << *it1 << " " << *it2 << " " << *it3 << endl;
return 0;
}
Output : 3 3 3
WARNINGS
If your compiler does not support default template parameters then
you need to always supply the Allocator template argument. For
instance you'll have to write:
vector<int,allocator<int> > instead of:
vector<int>
SEE ALSO
Function Object
STANDARDS CONFORMANCE
ANSI X3J16/ISO WG21 Joint C++ Committee
Standard C++ Library
Copyright 1996, Rogue Wave Software, Inc.
NAME
bind1st, bind2nd, binder1st, binder2nd - Templatized utilities to
bind values to function objects
SYNOPSIS
#include <functional>
template <class Operation>
class binder1st : public unary_function<typename
Operation::second_argument_type,
typename Operation::result_type> ;
template <class Operation, class T>
binder1st<Operation> bind1st (const Operation&, const T&);
template <class Operation>
class binder2nd : public unary_function<typename
Operation::first_argument_type,
typename Operation::result_type> ;
template <class Operation, class T>
binder2nd<Operation> bind2nd (const Operation&, const T&);
DESCRIPTION
Because so many functions provided by the standard library take
other functions as arguments, the library includes classes
that let you build new function objects out of old ones. Both
bind1st() and bind2nd() are functions that take as arguments
a binary function object f and a value x, and return,
respectively, classes binder1st and binder2nd. The underlying
function object must be a subclass of binary_function.
Class binder1st binds the value to the first argument of the binary
function, and binder2nd does the same thing for the second argument
of the function. The resulting classes can be used in place of a
unary predicate in other function calls.
For example, you could use the count_if algorithm to count all
elements in a vector that are less than or equal to 7, using
the following:
count_if (v.begin, v.end, bind1st(greater<int> (),7), littleNums)
This function adds one to littleNums each time the predicate is
true, i.e., each time 7 is greater than the element.
INTERFACE
// Class binder1st
template <class Operation>
class binder1st
: public unary_function<typename
Operation::second_argument_type,
typename Operation::result_type>
{
public:
typedef typename unary_function<typename
Operation::second_argument_type, typename
Operation::result_type>::argument_type argument_type;
typedef typename unary_function<typename
Operation::second_argument_type, typename
Operation::result_type>::result_type result_type;
binder1st(const Operation&,
const typename Operation::first_argument_type&);
result_type operator() (const argument_type&) const;
};
// Class binder2nd
template <class Operation>
class binder2nd
: public unary_function<typename
Operation::first_argument_type,
typename Operation::result_type>
{
public:
typedef typename unary_function<typename
Operation::first_argument_type, typename
Operation::result_type>::argument_type argument_type;
typedef typename unary_function<typename
Operation::first_argument_type, typename
Operation::result_type>::result_type result_type;
binder2nd(const Operation&,
const typename Operation::second_argument_type&);
result_type operator() (const argument_type&) const;
};
// Creator bind1st
template <class Operation, class T>
binder1st<Operation> bind1st (const Operation&, const T&);
// Creator bind2nd
template<class Operation, class T>
binder2nd <Operation> bind2nd(const Operation&, const T&);
EXAMPLE
//
// binders.cpp
//
#include <functional>
#include <algorithm>
#include <vector>
#include <iostream.h>
int main()
{
typedef vector<int>::iterator iterator;
int d1[4] = {1,2,3,4};
//
// Set up a vector
//
vector<int> v1(d1,d1 + 4);
//
// Create an 'equal to 3' unary predicate by binding 3 to
// the equal_to binary predicate.
//
binder1st<equal_to<int> > equal_to_3 =
bind1st(equal_to<int>(),3);
//
// Now use this new predicate in a call to find_if
//
iterator it1 = find_if(v1.begin(),v1.end(),equal_to_3);
//
// Even better, construct the new predicate on the fly
//
iterator it2 =
find_if(v1.begin(),v1.end(),bind1st(equal_to<int>(),3));
//
// And now the same thing using bind2nd
// Same result since == is commutative
//
iterator it3 =
find_if(v1.begin(),v1.end(),bind2nd(equal_to<int>(),3));
//
// it3 = v1.begin() + 2
//
// Output results
//
cout << *it1 << " " << *it2 << " " << *it3 << endl;
return 0;
}
Output : 3 3 3
WARNINGS
If your compiler does not support default template parameters then
you need to always supply the Allocator template argument. For
instance you'll have to write:
vector<int,allocator<int> > instead of:
vector<int>
SEE ALSO
Function Object
STANDARDS CONFORMANCE
ANSI X3J16/ISO WG21 Joint C++ Committee
Standard C++ Library
Copyright 1996, Rogue Wave Software, Inc.
NAME
bind1st, bind2nd, binder1st, binder2nd - Templatized utilities to
bind values to function objects
SYNOPSIS
#include <functional>
template <class Operation>
class binder1st : public unary_function<typename
Operation::second_argument_type,
typename Operation::result_type> ;
template <class Operation, class T>
binder1st<Operation> bind1st (const Operation&, const T&);
template <class Operation>
class binder2nd : public unary_function<typename
Operation::first_argument_type,
typename Operation::result_type> ;
template <class Operation, class T>
binder2nd<Operation> bind2nd (const Operation&, const T&);
DESCRIPTION
Because so many functions provided by the standard library take
other functions as arguments, the library includes classes
that let you build new function objects out of old ones. Both
bind1st() and bind2nd() are functions that take as arguments
a binary function object f and a value x, and return,
respectively, classes binder1st and binder2nd. The underlying
function object must be a subclass of binary_function.
Class binder1st binds the value to the first argument of the binary
function, and binder2nd does the same thing for the second
argument of the function. The resulting classes can be used in
place of a unary predicate in other function calls.
For example, you could use the count_if algorithm to count all
elements in a vector that are less than or equal to 7, using
the following:
count_if (v.begin, v.end, bind1st(greater<int> (),7), littleNums)
This function adds one to littleNums each time the predicate is
true, i.e., each time 7 is greater than the element.
INTERFACE
// Class binder1st
template <class Operation>
class binder1st
: public unary_function<typename
Operation::second_argument_type,
typename Operation::result_type>
{
public:
typedef typename unary_function<typename
Operation::second_argument_type, typename
Operation::result_type>::argument_type argument_type;
typedef typename unary_function<typename
Operation::second_argument_type, typename
Operation::result_type>::result_type result_type;
binder1st(const Operation&,
const typename Operation::first_argument_type&);
result_type operator() (const argument_type&) const;
};
// Class binder2nd
template <class Operation>
class binder2nd
: public unary_function<typename
Operation::first_argument_type,
typename Operation::result_type>
{
public:
typedef typename unary_function<typename
Operation::first_argument_type, typename
Operation::result_type>::argument_type argument_type;
typedef typename unary_function<typename
Operation::first_argument_type, typename
Operation::result_type>::result_type result_type;
binder2nd(const Operation&,
const typename Operation::second_argument_type&);
result_type operator() (const argument_type&) const;
};
// Creator bind1st
template <class Operation, class T>
binder1st<Operation> bind1st (const Operation&, const T&);
// Creator bind2nd
template<class Operation, class T>
binder2nd <Operation> bind2nd(const Operation&, const T&);
EXAMPLE
//
// binders.cpp
//
#include <functional>
#include <algorithm>
#include <vector>
#include <iostream.h>
int main()
{
typedef vector<int>::iterator iterator;
int d1[4] = {1,2,3,4};
//
// Set up a vector
//
vector<int> v1(d1,d1 + 4);
//
// Create an 'equal to 3' unary predicate by binding 3 to
// the equal_to binary predicate.
//
binder1st<equal_to<int> > equal_to_3 =
bind1st(equal_to<int>(),3);
//
// Now use this new predicate in a call to find_if
//
iterator it1 = find_if(v1.begin(),v1.end(),equal_to_3);
//
// Even better, construct the new predicate on the fly
//
iterator it2 =
find_if(v1.begin(),v1.end(),bind1st(equal_to<int>(),3));
//
// And now the same thing using bind2nd
// Same result since == is commutative
//
iterator it3 =
find_if(v1.begin(),v1.end(),bind2nd(equal_to<int>(),3));
//
// it3 = v1.begin() + 2
//
// Output results
//
cout << *it1 << " " << *it2 << " " << *it3 << endl;
return 0;
}
Output : 3 3 3
WARNINGS
If your compiler does not support default template parameters then
you need to always supply the Allocator template argument. For
instance you'll have to write:
vector<int,allocator<int> > instead of:
vector<int>
SEE ALSO
Function Object
STANDARDS CONFORMANCE
ANSI X3J16/ISO WG21 Joint C++ Committee
Standard C++ Library
Copyright 1996, Rogue Wave Software, Inc.
NAME
mem_fun, mem_fun1, mem_fun_ref, mem_fun_ref1 - Function objects
that adapt a pointer to a member function to work where a
global function is called for.
SYNOPSIS
#include <functional>
template <class S, class T> class mem_fun_t;
template <class S, class T, class A> class mem_fun1_t;
template <class S, class T> class mem_fun_ref_t;
template <class S, class T, class A> class mem_fun1_ref_t;
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_fun1(S, (T::*f)(A));
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_fun1_ref(S, (T::*f)(A));
DESCRIPTION
The mem_fun group of templates each encapsulates a pointer to a
member function. Each category of template (i.e. mem_fun, mem_fun1,
mem_fun_ref, or mem_fun1_ref) provides both a class template and a
function template, where the class is distinguished by the addition
of _t on the end of the name to identify it as a type.
The class's constructor takes a pointer to a member function, and
provides an operator() that forwards the call to that member
function. In this way the resulting object serves as a global
function object for that member function.
The accompanying function template simplifies the use of this
facility by constructing an instance of the class on the fly.
The library provides zero and one argument adaptors for containers
of pointers and containers of references (_ref). This
technique can be easily extended to include adaptors for two
argument functions, and so on.
INTERFACE
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);
};
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);
};
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_fun1(S, (T::*f)(A));
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);
};
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);
};
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_fun1_ref(S, (T::*f)(A));
EXAMPLE
//
// mem_fun example
//
#include <functional>
#include <list>
int main(void)
{
int a1[] = {2,1,5,6,4};
int a2[] = {11,4,67,3,14};
list<int> s1(a1,a1+5);
list<int> s2(a2,a2+5);
// Build a list of lists
list<list<int>* > l;
l.insert(l.begin(),s1);
l.insert(l.begin(),s2);
// Sort each list in the list
for_each(l.begin(),l.end(),mem_fun(&list<int>::sort));
}
SEE ALSO
binary_function, function_objects, pointer_to_unary_function,
ptr_fun
STANDARDS CONFORMANCE
ANSI X3J16/ISO WG21 Joint C++ Committee
Standard C++ Library
Copyright 1996, Rogue Wave Software, Inc.
NAME
mem_fun, mem_fun1, mem_fun_ref, mem_fun_ref1 - Function objects
that adapt a pointer to a member function to work where a global
function is called for.
SYNOPSIS
#include <functional>
template <class S, class T> class mem_fun_t;
template <class S, class T, class A> class mem_fun1_t;
template <class S, class T> class mem_fun_ref_t;
template <class S, class T, class A> class mem_fun1_ref_t;
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_fun1(S, (T::*f)(A));
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_fun1_ref(S, (T::*f)(A));
DESCRIPTION
The mem_fun group of templates each encapsulates a pointer to a
member function. Each category of template (i.e. mem_fun, mem_fun1,
mem_fun_ref,or mem_fun1_ref) provides both a class template and a
function template, where the class is distinguished by the addition
of _t on the end of the name to identify it as a type.
The class's constructor takes a pointer to a member function, and
provides an operator() that forwards the call to that member
function. In this way the resulting object serves as a global
function object for that member function.
The accompanying function template simplifies the use of this
facility by constructing an instance of the class on the fly.
The library provides zero and one argument adaptors for containers
of pointers and containers of references (_ref). This
technique can be easily extended to include adaptors for two
argument functions, and so on.
INTERFACE
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);
};
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);
};
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_fun1(S, (T::*f)(A));
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);
};
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);
};
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_fun1_ref(S, (T::*f)(A));
EXAMPLE
//
// mem_fun example
//
#include <functional>
#include <list>
int main(void)
{
int a1[] = {2,1,5,6,4};
int a2[] = {11,4,67,3,14};
list<int> s1(a1,a1+5);
list<int> s2(a2,a2+5);
// Build a list of lists
list<list<int>* > l;
l.insert(l.begin(),s1);
l.insert(l.begin(),s2);
// Sort each list in the list
for_each(l.begin(),l.end(),mem_fun(&list<int>::sort));
}
SEE ALSO
binary_function, function_objects, pointer_to_unary_function,
ptr_fun
STANDARDS CONFORMANCE
ANSI X3J16/ISO WG21 Joint C++ Committee
Standard C++ Library
Copyright 1996, Rogue Wave Software, Inc.
NAME
mem_fun, mem_fun1, mem_fun_ref, mem_fun_ref1 - Function objects
that adapt a pointer to a member function to work where a
global function is called for.
SYNOPSIS
#include <functional>
template <class S, class T> class mem_fun_t;
template <class S, class T, class A> class mem_fun1_t;
template <class S, class T> class mem_fun_ref_t;
template <class S, class T, class A> class mem_fun1_ref_t;
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_fun1(S, (T::*f)(A));
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_fun1_ref(S, (T::*f)(A));
DESCRIPTION
The mem_fun group of templates each encapsulates a pointer to a
member function. Each category of template (i.e. mem_fun, mem_fun1,
mem_fun_ref, or mem_fun1_ref) provides both a class template and a
function template, where the class is distinguished by the addition
of _t on the end of the name to identify it as a type.
The class's constructor takes a pointer to a member function, and
provides an operator() that forwards the call to that member
function. In this way the resulting object serves as a global
function object for that member function.
The accompanying function template simplifies the use of this
facility by constructing an instance of the class on the fly.
The library provides zero and one argument adaptors for containers
of pointers and containers of references (_ref). This
technique can be easily extended to include adaptors for two
argument functions, and so on.
INTERFACE
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);
};
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);
};
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_fun1(S, (T::*f)(A));
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);
};
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);
};
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_fun1_ref(S, (T::*f)(A));
EXAMPLE
//
// mem_fun example
//
#include <functional>
#include <list>
int main(void)
{
int a1[] = {2,1,5,6,4};
int a2[] = {11,4,67,3,14};
list<int> s1(a1,a1+5);
list<int> s2(a2,a2+5);
// Build a list of lists
list<list<int>* > l;
l.insert(l.begin(),s1);
l.insert(l.begin(),s2);
// Sort each list in the list
for_each(l.begin(),l.end(),mem_fun(&list<int>::sort));
}
SEE ALSO
binary_function, function_objects, pointer_to_unary_function, ptr_fun
STANDARDS CONFORMANCE
ANSI X3J16/ISO WG21 Joint C++ Committee
Standard C++ Library
Copyright 1996, Rogue Wave Software, Inc.
NAME
mem_fun, mem_fun1, mem_fun_ref, mem_fun_ref1 - Function objects
that adapt a pointer to a member function to work where a global
function is called for.
SYNOPSIS
#include <functional>
template <class S, class T> class mem_fun_t;
template <class S, class T, class A> class mem_fun1_t;
template <class S, class T> class mem_fun_ref_t;
template <class S, class T, class A> class mem_fun1_ref_t;
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_fun1(S, (T::*f)(A));
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_fun1_ref(S, (T::*f)(A));
DESCRIPTION
The mem_fun group of templates each encapsulates a pointer to a
member function. Each category of template (i.e. mem_fun, mem_fun1,
mem_fun_ref, or mem_fun1_ref) provides both a class template and a
function template, where the class is distinguished by the addition
of _t on the end of the name to identify it as a type.
The class's constructor takes a pointer to a member function, and
provides an operator() that forwards the call to that member
function. In this way the resulting object serves as a global
function object for that member function.
The accompanying function template simplifies the use of this
facility by constructing an instance of the class on the fly.
The library provides zero and one argument adaptors for containers
of pointers and containers of references (_ref). This
technique can be easily extended to include adaptors for two
argument functions, and so on.
INTERFACE
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);
};
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);
};
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_fun1(S, (T::*f)(A));
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);
};
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);
};
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_fun1_ref(S, (T::*f)(A));
EXAMPLE
//
// mem_fun example
//
#include <functional>
#include <list>
int main(void)
{
int a1[] = {2,1,5,6,4};
int a2[] = {11,4,67,3,14};
list<int> s1(a1,a1+5);
list<int> s2(a2,a2+5);
// Build a list of lists
list<list<int>* > l;
l.insert(l.begin(),s1);
l.insert(l.begin(),s2);
// Sort each list in the list
for_each(l.begin(),l.end(),mem_fun(&list<int>::sort));
}
SEE ALSO
binary_function, function_objects, pointer_to_unary_function, ptr_fun
STANDARDS CONFORMANCE
ANSI X3J16/ISO WG21 Joint C++ Committee