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<H2>logical_or</H2>
<P><B>Library:</B>&nbsp;&nbsp;<A HREF="2-4.html">General utilities</A></P>

<PRE><HR><B><I>Does not inherit</I></B><HR></PRE>

<UL>
<LI><A HREF="#sec1">Local Index</A></LI>
<LI><A HREF="#sec2">Summary</A></LI>
<LI><A HREF="#sec3">Synopsis</A></LI>
<LI><A HREF="#sec4">Description</A></LI>
<LI><A HREF="#sec5">Interface</A></LI>
<LI><A HREF="#sec6">See Also</A></LI>
<LI><A HREF="#sec7">Standards Conformance</A></LI>
</UL>
<A NAME="sec1"><H3>Local Index</H3></A>
No Entries
<A NAME="sec2"><H3>Summary</H3></A>
<P>A binary function object that returns <SAMP>true</SAMP> if either of its arguments are <SAMP>true</SAMP></P>
<A NAME="sec3"><H3>Synopsis</H3></A>

<PRE>#include &lt;functional&gt;

namespace std {
  template &lt;class T&gt;
  struct logical_or;
}
</PRE>
<A NAME="sec4"><H3>Description</H3></A>
<P><B><I>logical_or</I></B> 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</I></B> object to any algorithm that requires a binary function. For example, the <SAMP><A HREF="transform.html">transform()</A></SAMP> algorithm applies a binary operation to corresponding values in two collections and stores the result of the function. <B><I>logical_or</I></B> is used in that algorithm in the following manner:</P>

<UL><PRE>
list&lt;bool&gt; list1;
list&lt;bool&gt; list2;
list&lt;bool&gt; listResult;
.
.
.
transform(list1.begin(), list1.end(),
          list2.begin(),
          listResult.begin(), <B>logical_or&lt;bool&gt;()</B>);
</PRE></UL>
<P>After this call to <SAMP><A HREF="transform.html">transform()</A></SAMP>, <SAMP>listResult(n)</SAMP> contains a <SAMP>1</SAMP> (<SAMP>true</SAMP>) if either <SAMP>list1(n)</SAMP> or <SAMP>list2(n)</SAMP> is <SAMP>true</SAMP>, or a <SAMP>0</SAMP> (<SAMP>false</SAMP>) if both <SAMP>list1(n)</SAMP> and <SAMP>list2(n)</SAMP> are <SAMP>false</SAMP>.</P>
<A NAME="sec5"><H3>Interface</H3></A>

<UL><PRE>namespace std {

  template &lt;class T&gt;
  struct logical_or : binary_function&lt;T, T, bool&gt; {
    bool operator()(const T&amp;, const T&amp;) const;
  };
}
</PRE></UL>
<A NAME="sec6"><H3>See Also</H3></A>
<P><B><I><A HREF="binary-function.html">binary_function</A></I></B>, <A HREF="functionobjects.html">Function Objects</A></P>
<A NAME="sec7"><H3>Standards Conformance</H3></A>
<P><I>ISO/IEC 14882:1998 -- International Standard for Information Systems -- Programming Language C++, Section 20.3.4</I></P>

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