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

 <PRE><HR><B><I>Function</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>A function adaptor that creates a function object from a pointer to a function </P>
 <A NAME="sec3"><H3>Synopsis</H3></A>

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

 namespace std {
   template&lt;class Arg, class Result&gt;
   pointer_to_unary_function&lt;Arg, Result&gt;
   ptr_fun(Result (*f)(Arg));

   template&lt;class Arg1, class Arg2, class Result&gt;
   pointer_to_binary_function&lt;Arg1, Arg2, Result&gt;
   ptr_fun(Result (*x)(Arg1, Arg2));
 }
 </PRE>
 <A NAME="sec4"><H3>Description</H3></A>
 <P>The <B><I><A HREF="pointer-to-unary-function.html">pointer_to_unary_function</A></I></B> and <B><I><A HREF="pointer-to-binary-function.html">pointer_to_binary_function</A></I></B> classes encapsulate pointers to functions, and use <SAMP>operator()</SAMP> so that the resulting object serves as a function object for the function.</P>
 <P>The <SAMP>ptr_fun()</SAMP> function is overloaded to create instances of <B><I><A HREF="pointer-to-unary-function.html">pointer_to_unary_function</A></I></B> or <B><I><A HREF="pointer-to-binary-function.html">pointer_to_binary_function</A></I></B> when included with the appropriate pointer to a function. </P>
 <A NAME="sec5"><H3>Example</H3></A>

 <UL><PRE>//
 //  pnt2fnct.cpp
 //

 #include &lt;algorithm&gt;    // for copy, transform
 #include &lt;functional&gt;   // for ptr_fun
 #include &lt;iostream&gt;     // cout, endl
 #include &lt;iterator&gt;     // for ostream_iterator
 #include &lt;deque&gt;        // for deque
 #include &lt;vector&gt;       // for vector


 int factorial (int x)
 {
     return x &gt; 1 ? x * factorial (x - 1) : x;
 }


 int main ()
 {
     typedef std::deque&lt;int, std::allocator&lt;int&gt; &gt;  Deque;
     typedef std::vector&lt;int, std::allocator&lt;int&gt; &gt; Vector;
     typedef std::ostream_iterator&lt;int, char,
                                   std::char_traits&lt;char&gt; &gt;
             Iter;

     // Initialize a deque with an array of integers.
     const Deque::value_type a[] = { 1, 2, 3, 4, 5, 6, 7 };
     Deque d (a + 0, a + sizeof a / sizeof *a);

     // Create an empty vector to store the factorials.
     Vector v (Vector::size_type (7));

     // Compute factorials of the contents of 'd' and
     // store results in 'v'.
     std::transform (d.begin (), d.end (), v.begin (),
                     std::ptr_fun (factorial));

     // Print the results.
     std::cout &lt;&lt; "The following numbers: \n     ";
     std::copy (d.begin (), d.end (), Iter (std::cout," "));

     std::cout &lt;&lt; "\n\nHave the factorials: \n     ";
     std::copy (v.begin (), v.end (), Iter (std::cout, " "));
     std::cout &lt;&lt; std::endl;

     return 0;
 }


 Program Output:
 </PRE></UL>
 <UL><PRE>The following numbers:
      1 2 3 4 5 6 7

 Have the factorials:
      1 2 6 24 120 720 5040
 </PRE></UL>
 <A NAME="sec6"><H3>See Also</H3></A>
 <P><A HREF="functionobjects.html">Function Objects</A>, <B><I><A HREF="pointer-to-binary-function.html">pointer_to_binary_function</A></I></B>, <B><I><A HREF="pointer-to-unary-function.html">pointer_to_unary_function</A></I></B>, <B><I><A HREF="mem-fun.html">mem_fun</A></I></B></P>
 <A NAME="sec7"><H3>Standards Conformance</H3></A>
 <P><I>ISO/IEC 14882:1998 -- International Standard for Information Systems -- Programming Language C++, Section 20.3.7</I></P>

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	<H2>ptr_fun()</H2>
	<P><B>Library:</B>  <A HREF="2-4.html">General utilities</A></P>

	<PRE><HR><B><I>Function</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>A function adaptor that creates a function object from a pointer to a function </P>
	<A NAME="sec3"><H3>Synopsis</H3></A>

	<PRE>#include <functional>

	namespace std {
	template<class Arg, class Result>
	pointer_to_unary_function<Arg, Result>
	ptr_fun(Result (*f)(Arg));

	template<class Arg1, class Arg2, class Result>
	pointer_to_binary_function<Arg1, Arg2, Result>
	ptr_fun(Result (*x)(Arg1, Arg2));
	}
	</PRE>
	<A NAME="sec4"><H3>Description</H3></A>
	<P>The <B><I><A HREF="pointer-to-unary-function.html">pointer_to_unary_function</A></I></B> and <B><I><A HREF="pointer-to-binary-function.html">pointer_to_binary_function</A></I></B> classes encapsulate pointers to functions, and use <SAMP>operator()</SAMP> so that the resulting object serves as a function object for the function.</P>
	<P>The <SAMP>ptr_fun()</SAMP> function is overloaded to create instances of <B><I><A HREF="pointer-to-unary-function.html">pointer_to_unary_function</A></I></B> or <B><I><A HREF="pointer-to-binary-function.html">pointer_to_binary_function</A></I></B> when included with the appropriate pointer to a function. </P>
	<A NAME="sec5"><H3>Example</H3></A>

	<UL><PRE>//
	// pnt2fnct.cpp
	//

	#include <algorithm> // for copy, transform
	#include <functional> // for ptr_fun
	#include <iostream> // cout, endl
	#include <iterator> // for ostream_iterator
	#include <deque> // for deque
	#include <vector> // for vector


	int factorial (int x)
	{
	return x > 1 ? x * factorial (x - 1) : x;
	}


	int main ()
	{
	typedef std::deque<int, std::allocator<int> > Deque;
	typedef std::vector<int, std::allocator<int> > Vector;
	typedef std::ostream_iterator<int, char,
	std::char_traits<char> >
	Iter;

	// Initialize a deque with an array of integers.
	const Deque::value_type a[] = { 1, 2, 3, 4, 5, 6, 7 };
	Deque d (a + 0, a + sizeof a / sizeof *a);

	// Create an empty vector to store the factorials.
	Vector v (Vector::size_type (7));

	// Compute factorials of the contents of 'd' and
	// store results in 'v'.
	std::transform (d.begin (), d.end (), v.begin (),
	std::ptr_fun (factorial));

	// Print the results.
	std::cout << "The following numbers: \n ";
	std::copy (d.begin (), d.end (), Iter (std::cout," "));

	std::cout << "\n\nHave the factorials: \n ";
	std::copy (v.begin (), v.end (), Iter (std::cout, " "));
	std::cout << std::endl;

	return 0;
	}


	Program Output:
	</PRE></UL>
	<UL><PRE>The following numbers:
	1 2 3 4 5 6 7

	Have the factorials:
	1 2 6 24 120 720 5040
	</PRE></UL>
	<A NAME="sec6"><H3>See Also</H3></A>
	<P><A HREF="functionobjects.html">Function Objects</A>, <B><I><A HREF="pointer-to-binary-function.html">pointer_to_binary_function</A></I></B>, <B><I><A HREF="pointer-to-unary-function.html">pointer_to_unary_function</A></I></B>, <B><I><A HREF="mem-fun.html">mem_fun</A></I></B></P>
	<A NAME="sec7"><H3>Standards Conformance</H3></A>
	<P><I>ISO/IEC 14882:1998 -- International Standard for Information Systems -- Programming Language C++, Section 20.3.7</I></P>

	<BR>
	<HR>
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