.\" ident @(#)plus.3
.\" Standard Template Library
.\" $$RW_INSERT_HEADER "slyrs.man"
.TH plus 3C++ "02 Apr 1998" "Rogue Wave Software" "-"
.ce2
Standard C++ Library   
Copyright 1998, Rogue Wave Software, Inc.   

.SH NAME

\f2plus\fP

\ - A binary function object that returns the result of adding its first and second arguments.



.SH  SYNOPSIS


.br
#include <functional>
.br
template<class T>
.br
struct plus : public binary_function<T, T, T> ;



.SH  DESCRIPTION


plus is a binary function object. Its \f2operator()\fP returns the result of adding \f2x\fP and \f2y\fP. You can pass a plus object to any algorithm that uses a binary function. For example, the transform algorithm applies a binary operation to corresponding values in two collections and stores the result. plus would be used in that algorithm in the following manner:


.br
vector<int> vec1;
.br
vector<int> vec2;
.br
vector<int> vecResult;
.br
.
.br
.
.br
.
.br
transform(vec1.begin(), vec1.end(), vec2.begin(),
.RE
.RS 9
vecResult.begin(), plus<int>());
.RE

After this call to transform, \f2vecResult(n)\fP contains \f2vec1(n)\fP plus \f2vec2(n)\fP.



.SH  INTERFACE


.RE
.RS 0
template<class T>
.br
struct plus : binary_function<T, T, T> {
.RE
.RS 1
T operator() (const T&, const T&) const;
.RE
.RS 0
};



.SH  WARNINGS


If your compiler does not support default template parameters, you always need to supply the \f2Allocator\fP template argument. For instance, you need to write:

\f2vector<int, allocator<int> >\fP

instead of:

\f2vector<int>\fP

If your compiler does not support namespaces, then you do not need the using declaration for \f2std\fP.



.SH  SEE ALSO


binary_function, Function_Objects