| United States |
|
|
|
Operators
Standard C++ Library Copyright 1996, Rogue Wave Software, Inc.NAME
operator!=, operator>, operator<=, operator>= - Operators for the C++ Standard C++ Library
SYNOPSIS
#include <utility>
namespace rel_ops {
template <class T> bool operator!= (const T&, const T&);
template <class T> bool operator> (const T&, const T&);
template <class T> bool operator<= (const T&, const T&);
template <class T> bool operator>= (const T&, const T&); }
DESCRIPTION
To avoid redundant definitions of operator!= out of operator== and of operators >, <=, and >= out of operator<, the library provides these definitions:
operator!= returns !(x==y), operator> returns y<x, operator<= returns !(y<x), and operator>= returns !(x<y).
To avoid clashes with other global operators these definitions are contained in the namespace rel_ops. To use them either scope explicitly or provide a using declaration (e.g. using_namespace_rel_ops).
STANDARDS CONFORMANCE ANSI X3J16/ISO WG21 Joint C++ Committee
pair
Standard C++ Library Copyright 1996, Rogue Wave Software, Inc.NAME
pair - A template for heterogeneous pairs of values.
SYNOPSIS
#include <utility>
template <class T1, class T2> struct pair ;
DESCRIPTION
The pair class provides a template for encapsulating pairs of values that may be of different types.
INTERFACE
template <class T1, class T2> struct pair { T1 first; T2 second; pair(); pair (const T1&, const T2&); ~pair(); };
template <class T1, class T2> bool operator== (const pair<T1, T2>&, const pair T1, T2>&);
template <class T1, class T2> bool operator!= (const pair<T1, T2>&, const pair T1, T2>&);
template <class T1, class T2> bool operator< (const pair<T1, T2>&, const pair T1, T2>&);
template <class T1, class T2> bool operator> (const pair<T1, T2>&, const pair T1, T2>&);
template <class T1, class T2> bool operator<= (const pair<T1, T2>&, const pair T1, T2>&);
template <class T1, class T2> bool operator>= (const pair<T1, T2>&, const pair T1, T2>&);
template <class T1, class T2> pair<T1,T2> make_pair (const T1&, const T2&);
CONSTRUCTORS AND DESTRUCTORS
pair (); Default constructor. Initializes first and second using their default constructors.
pair (const T1& x, const T2& y); The constructor creates a pair of types T1 and T2, making the necessary conversions in x and y.
~pair (); Destructor.
NON-MEMBER OPERATORS
template <class T1, class T2> bool operator== (const pair<T1, T2>& x, const pair T1, T2>& y); Returns true if (x.first == y.first && x.second == y.second) is true. Otherwise it returns false.
template <class T1, class T2> bool operator!= (const pair<T1, T2>& x, const pair T1, T2>& y); Returns !(x==y).
template <class T1, class T2> bool operator< (const pair<T1, T2>& x, const pair T1, T2>& y); Returns true if (x.first < y.first || (!(y.first < x.first) && x.second < y.second)) is true. Otherwise it returns false.
template <class T1, class T2> bool operator> (const pair<T1, T2>& x, const pair T1, T2>& y); Returns y < x.
template <class T1, class T2> bool operator<= (const pair<T1, T2>& x, const pair T1, T2>& y); Returns !(y < x).
template <class T1, class T2> bool operator>= (const pair<T1, T2>& x, const pair T1, T2>& y); Returns !(x < y).
NON-MEMBER FUNCTIONS
template <class T1, class T2> pair<T1,T2> make_pair(x,y); make_pair(x,y) creates a pair by deducing and returning the types of x and y.
STANDARDS CONFORMANCE ANSI X3J16/ISO WG21 Joint C++ Committee
pointer_to_binary_function
Standard C++ LibraryNAME
pointer_to_binary_function - A function object which adapts a pointer to a binary function to work where a binary_function is called for.
SYNOPSIS
#include <functional>
template <class Arg1, class Arg2, class Result> class pointer_to_binary_function : public binary_function<Arg1, Arg2, Result> ;
DESCRIPTION
The pointer_to_binary_function class encapsulates a pointer to a two- argument function. The class provides an operator() so that the resulting object serves as a binary function object for that function.
The ptr_fun function is overloaded to create instances of a pointer_to_binary_function when provided with the appropriate pointer to a function.
INTERFACE
template <class Arg1, class Arg2, class Result>
class pointer_to_binary_function : public binary_function<Arg1, Arg2, Result> { public: typedef typename binary_function<Arg1, Arg2, Result>::second_argument_type second_argument_type; typedef typename binary_function<Arg1, Arg2, Result>::first_argument_type first_argument_type; typedef typename binary_function<Arg1, Arg2, Result>::result_type result_type; explicit pointer_to_binary_function (Result (*f)(Arg1, Arg2)); Result operator() (const Arg1&, const Arg2&) const; };
template<class Arg1, class Arg2, class Result> pointer_to_binary_function<Arg1, Arg2, Result> ptr_fun (Result (*x)(Arg1, Arg2));
SEE ALSO
binary_function, function_objects, pointer_to_unary_function, ptr_fun
STANDARDS CONFORMANCE ANSI X3J16/ISO WG21 Joint C++ Committee
pointer_to_unary_function
Standard C++ Library Copyright 1996, Rogue Wave Software, Inc.NAME
pointer_to_unary_function - A function object class that adapts a pointer to a function to work where a unary_function is called for.
SYNOPSIS
#include <functional>
template <class Arg, class Result> class pointer_to_unary_function : public unary_function<Arg, Result>;
DESCRIPTION
The pointer_to_unary_function class encapsulates a pointer to a single-argument function. The class provides an operator() so that the resulting object serves as a function object for that function.
The ptr_fun function is overloaded to create instances of pointer_to_unary_function when provided with the appropriate pointer to a function.
INTERFACE
template <class Arg, class Result> class pointer_to_unary_function : public unary_function<Arg, Result> {
public: typedef typename unary_function<Arg,Result>::argument_type argument_type; typedef typename unary_function<Arg,Result>::result_type result_type; explicit pointer_to_unary_function (Result (*f)(Arg)); Result operator() (const Arg&) const; };
template<class Arg, class Result> pointer_to_unary_function<Arg, Result> ptr_fun (Result (*f)(Arg));
SEE ALSO
function_objects, pointer_to_binary_function, ptr_fun, unary_function
STANDARDS CONFORMANCE ANSI X3J16/ISO WG21 Joint C++ Committee
ptr_fun
Standard C++ Library Copyright 1996, Rogue Wave Software, Inc.NAME
ptr_fun - A function that is overloaded to adapt a pointer to a function to work where a function is called for.
SYNOPSIS
#include <functional>
template<class Arg, class Result> pointer_to_unary_function<Arg, Result> ptr_fun (Result (*f)(Arg));
template<class Arg1, class Arg2, class Result> pointer_to_binary_function<Arg1, Arg2, Result> ptr_fun (Result (*x)(Arg1, Arg2));
DESCRIPTION
The pointer_to_unary_function and pointer_to_binary_function classes encapsulate pointers to functions and provide an operator() so that the resulting object serves as a function object for the function.
The ptr_fun function is overloaded to create instances of pointer_to_unary_function or pointer_to_binary_function when provided with the appropriate pointer to a function.
EXAMPLE
// // pnt2fnct.cpp // #include <functional> #include <deque> #include <vector> #include <algorithm> #include <iostream.h>
//Create a function int factorial(int x) { int result = 1; for(int i = 2; i <= x; i++) result *= i; return result; }
int main() { //Initialize a deque with an array of ints int init[7] = {1,2,3,4,5,6,7}; deque<int> d(init, init+7);
//Create an empty vector to store the factorials vector<int> v((size_t)7);
//Transform the numbers in the deque to their factorials and //store in the vector transform(d.begin(), d.end(), v.begin(), ptr_fun(factorial));
//Print the results cout << "The following numbers: " << endl << " "; copy(d.begin(),d.end(),ostream_iterator<int,char>(cout," "));
cout << endl << endl; cout << "Have the factorials: " << endl << " "; copy(v.begin(),v.end(),ostream_iterator<int,char>(cout," "));
return 0; }
Output : The following numbers: 1 2 3 4 5 6 7 Have the factorials: 1 2 6 24 120 720 5040
WARNING
If your compiler does not support default template parameters, you need to always supply the Allocator template argument. For instance, you will need to write :
vector<int, allocator<int> >
instead of :
vector<int>
SEE ALSO
function_objects, pointer_to_binary_function, pointer_to_unary_function
STANDARDS CONFORMANCE ANSI X3J16/ISO WG21 Joint C++ Committee
|
