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<H2>logical_not</H2>
<HR><PRE>     Function<B><I> </I></B>Object</B></I>
</PRE><HR>
<A NAME="Summary"><H3>Summary</H3></A>
<P>Unary function object that returns <SAMP>true</SAMP> if its argument is <SAMP>false</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 &#60;functional></PRE>
<PRE>
template &#60;class T>
struct <B>logical_not</B> : unary_function&#60;T, bool> ;
</PRE>
<A NAME="Description"><H3>Description</H3></A>
<P><B><I>logical_not</B></I> is a unary function object.  Its <SAMP>operator()</SAMP> returns <SAMP>true</SAMP> if its argument is <SAMP>false</SAMP>.  You can pass a <B><I>logical_not</B></I> object to any algorithm that requires a unary function.  For example, the <A HREF="rep_6837.htm"><B><I>replace_if</B></I></A> algorithm replaces an element with another value if the result of a unary operation is true.   <B><I>logical_not</B></I> is used in that algorithm in the following manner:</P>
<PRE>vector&#60;int> vec1;</PRE>
<PRE>.
.
.
void replace_if(vec1.begin(), vec1.end(),
                <B>logical_not&#60;int>()</B>,1);
</PRE><P>This call to <A HREF="rep_6837.htm"><B><I>replace_if</B></I></A> replaces all zeros in the <SAMP>vec1</SAMP> with "1".</P>
<A NAME="Interface"><H3>Interface</H3></A>
<PRE>template &#60;class T></PRE>
<PRE>struct logical_not : unary_function&#60;T, bool> {
  typedef typename unary_function&#60;T, bool>::argument_type 
                                            argument_type;
  typedef typename unary_function&#60;T, bool>::result_type result_type;
  bool operator() (const T&#38;) 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&#60;int, allocator></SAMP></P>
<P>instead of : </P>
<P><SAMP>vector&#60;int></SAMP></P>
<A NAME="See Also"><H3>See Also</H3></A>
<P><A HREF="Fun_7437.htm"><B><I>Function Objects</B></I></A>, <A HREF="una_4659.htm"><B><I>unary_function</B></I></A></P>
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