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<P>©Copyright 1996 Rogue Wave Software</P>
<H2>logical_or</H2>
<HR><PRE> Function Object</PRE><HR>
<A NAME="Summary"><H3>Summary</H3></A>
<P>Binary function object that returns <SAMP>true</SAMP> if either of its arguments are <SAMP>true</SAMP>.</P>
<H3>Contents</H3>
<UL>
<A HREF="#Synopsis"><LI>Synopsis</LI></A>
<A HREF="#Description"><LI>Description</LI></A>
<A HREF="#Interface"><LI>Interface</LI></A>
<A HREF="#Warning"><LI>Warning</LI></A>
<A HREF="#See Also"><LI>See Also</LI></A>
</UL>
<A NAME="Synopsis"><H3>Synopsis</H3></A>
<PRE>#include <functional></PRE>
<PRE>
template <class T>
struct <B>logical_or</B> : binary_function<T, T, bool> ;
</PRE>
<A NAME="Description"><H3>Description</H3></A>
<P><B><I>logical_or</B></I> is a binary function object. Its <SAMP>operator()</SAMP> returns <SAMP>true</SAMP> if either <SAMP>x</SAMP> or <SAMP>y</SAMP> are <SAMP>true</SAMP>. You can pass a <B><I>logical_or</B></I> object to any algorithm that requires a binary function. For example, the <A HREF="tra_4787.htm"><B><I>transform</B></I></A> algorithm applies a binary operation to corresponding values in two collections and stores the result of the function. <B><I>logical_or</B></I> is used in that algorithm in the following manner:</P>
<PRE>vector<bool> vec1;</PRE>
<PRE>vector<bool> vec2;
vector<bool> vecResult;
.
.
.
transform(vec1.begin(), vec1.end(),
vec2.begin(),
vecResult.begin(), <B>logical_or<bool>()</B>);
</PRE><P>After this call to <A HREF="tra_4787.htm"><B><I>transform</B></I></A>, <SAMP>vecResult(n)</SAMP> will contain a "1" (<SAMP>true</SAMP>) if either <SAMP>vec1(n)</SAMP> or <SAMP>vec2(n)</SAMP> is <SAMP>true</SAMP> or a "0" (<SAMP>false</SAMP>) if both <SAMP>vec1(n)</SAMP> and <SAMP>vec2(n)</SAMP> are <SAMP>false</SAMP>.</P>
<A NAME="Interface"><H3>Interface</H3></A>
<PRE>template <class T></PRE>
<PRE>struct logical_or : binary_function<T, T, bool> {
typedef typename binary_function<T, T, bool>::second_argument_type
second_argument_type;
typedef typename binary_function<T, T, bool>::first_argument_type
first_argument_type;
typedef typename binary_function<T, T, bool>::result_type
result_type;
bool operator() (const T&, const T&) const;
};
</PRE>
<A NAME="Warning"><H3>Warning</H3></A>
<P>If your compiler does not support default template parameters, you will need to always supply the <SAMP>Allocator</SAMP> template arguement. For instance, you will have to write :</P>
<P><SAMP>vector<bool, allocator></SAMP></P>
<P>instead of: </P>
<P><SAMP>vector<bool></SAMP></P>
<A NAME="See Also"><H3>See Also</H3></A>
<P><A HREF="bin_7851.htm"><B><I>binary_function</B></I></A>, <A HREF="Fun_7437.htm"><B><I>Function Objects</B></I></A></P>
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