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<H2>mem_fun, mem_fun_ref</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">Example</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>Function objects that adapt a pointer to a member function, to take the place of a global function</P>
<A NAME="sec3"><H3>Synopsis</H3></A>

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

namespace std {
  template &lt;class S, class T&gt; class mem_fun_t; 
  template &lt;class S, class T, class A&gt; class mem_fun1_t;
  template &lt;class S, class T&gt; class mem_fun_ref_t; 
  template &lt;class S, class T, class A&gt; class mem_fun1_ref_t;

  template &lt;class S, class T&gt; class const_mem_fun_t; 
  template &lt;class S, class T, class A&gt; class const_mem_fun1_t;
  template &lt;class S, class T&gt; class const_mem_fun_ref_t; 
  template &lt;class S, class T, class A&gt;
  class const_mem_fun1_ref_t;

  template&lt;class S, class T&gt; mem_fun_t&lt;S,T&gt;
  mem_fun(S, (T::*f)());
  template&lt;class S, class T&gt; mem_fun_ref_t&lt;S,T&gt;
  mem_fun_ref(S, (T::*f)());

  template&lt;class S, class T. class A&gt; mem_fun1_t&lt;S,T,A&gt;
  mem_fun(S, (T::*f)(A));
  template&lt;class S, class T, class A&gt; mem_fun1_ref_t&lt;S,T,A&gt;
  mem_fun_ref(S, (T::*f)(A));

  template&lt;class S, class T&gt; const_mem_fun_t&lt;S,T&gt;
  mem_fun(S, (T::*f)() const);
  template&lt;class S, class T&gt; const_mem_fun_ref_t&lt;S,T&gt;
  mem_fun_ref(S, (T::*f)() const);

  template&lt;class S, class T, class A&gt; const_mem_fun1_t&lt;S,T,A&gt;
  mem_fun(S, (T::*f)(A) const);
  template&lt;class S, class T, class A&gt;
  const_mem_fun1_ref_t&lt;S,T,A&gt;
  mem_fun_ref(S, (T::*f)(A) const);
}
</PRE>
<A NAME="sec4"><H3>Description</H3></A>
<P>The <B><I><A HREF="mem-fun.html">mem_fun</A></I></B> group of templates encapsulates a pointer to a member function. Each category of template (<B><I>mem_fun</I></B> or <B><I><A HREF="mem-fun.html">mem_fun_ref</A></I></B>) includes both a class template and a function template, where the class is distinguished by the addition of <SAMP>_t</SAMP> on the end of the name to identify it as a type. A set of class templates for const member functions exists, each with <SAMP>const_</SAMP> prepended to the name.</P>
<P>The class's constructor takes a pointer to a member function and uses <SAMP>operator()</SAMP> to forward the call to that member function. The resulting object serves as a global function object for that member function. </P>
<P>The accompanying function template simplifies the use of this facility by constructing an instance of the class on the fly. </P>
<P>The library includes zero and one argument adaptors for containers of pointers and containers of references (<SAMP>_ref</SAMP>). This technique can be easily extended to include adaptors for two argument functions, and so on. </P>
<A NAME="sec5"><H3>Example</H3></A>

<UL><PRE>//
// mem_fun example
//

#include &lt;functional&gt;
#include &lt;list&gt;
using namespace std;

int main(void)
{
  int a1[] = {2,1,5,6,4};
  int a2[] = {11,4,67,3,14};
  list&lt;int&gt; s1(a1,a1+5);
  list&lt;int&gt; s2(a2,a2+5);

  // Build a list of lists
  list&lt;list&lt;int&gt;* &gt; l;
  l.insert(l.begin(),s1);
  l.insert(l.begin(),s2);

  // Sort each list in the list
  for_each(l.begin(),l.end(),mem_fun(&amp;list&lt;int&gt;::sort));
}
</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>, <B><I><A HREF="pointer-to-unary-function.html">pointer_to_unary_function</A></I></B>, <SAMP><A HREF="ptr-fun.html">ptr_fun()</A></SAMP></P>
<A NAME="sec7"><H3>Standards Conformance</H3></A>
<P><I>ISO/IEC 14882:1998 -- International Standard for Information Systems -- Programming Language C++, Section 20.3.8</I></P>

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