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<H1>ptr_fun</H1>

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<TD Align=left VAlign=top><b>Categories</b>: functors, adaptors</TD>
<TD Align=right VAlign=top><b>Component type</b>: function</TD>
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<h3>Prototype</h3>
<pre>
template &lt;class Arg, class Result&gt;
pointer_to_unary_function&lt;Arg, Result&gt; 
ptr_fun(Result (*x)(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>                   
<h3>Description</h3>
<tt>Ptr_fun</tt> takes a function pointer as its argument and
returns a function pointer adaptor, a type of <A href="functors.html">function object</A>.
It is actually two different functions, not one (that is, the name
<tt>ptr_fun</tt> is overloaded).  If its argument is of type
<tt>Result (*)(Arg)</tt> then <tt>ptr_fun</tt> creates a 
<tt><A href="pointer_to_unary_function.html">pointer_to_unary_function</A></tt>, and if its argument is of type
<tt>Result (*)(Arg1, Arg2)</tt> then <tt>ptr_fun</tt> creates a
<tt><A href="pointer_to_binary_function.html">pointer_to_binary_function</A></tt>.
<h3>Definition</h3>
Defined in <A href="function.h">function.h</A>.
<h3>Requirements on types</h3>
The argument must be a pointer to a function that takes either 
one or two arguments.  The argument type(s) and the return type
of the function are arbitrary, with the restriction that the function
must return a value; it may not be a <tt>void</tt> function.
<h3>Preconditions</h3>
<h3>Complexity</h3>
<h3>Example</h3>
See the examples in the discussions of <tt><A href="pointer_to_unary_function.html">pointer_to_unary_function</A></tt>
and <tt><A href="pointer_to_binary_function.html">pointer_to_binary_function</A></tt>.
<h3>Notes</h3>
<h3>See also</h3>
<A href="functors.html">Function Objects</A>, <tt><A href="pointer_to_unary_function.html" tppabs="http://www.sgi.com/Technology/STL/pointer_to_unary_function.shtml">pointer_to_unary_function</A></tt>,
<tt><A href="pointer_to_binary_function.html">pointer_to_binary_function</A></tt>, <A href="AdaptableUnaryFunction.html" tppabs="http://www.sgi.com/Technology/STL/AdaptableUnaryFunction.shtml">Adaptable Unary Function</A>,
<A href="AdaptableBinaryFunction.html">Adaptable Binary Function</A> 

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