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| 22 | <title>Function Pointers (GNU C Language Manual)</title>
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| 30 | <link href="Symbol-Index.html" rel="index" title="Symbol Index">
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| 31 | <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
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| 32 | <link href="Functions.html" rel="up" title="Functions">
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| 33 | <link href="Declaring-Function-Pointers.html" rel="next" title="Declaring Function Pointers">
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| 55 | </head>
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| 57 | <body lang="en">
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| 58 | <span id="Function-Pointers"></span><div class="header">
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| 59 | <p>
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| 60 | Next: <a href="The-main-Function.html" accesskey="n" rel="next">The main Function</a>, Previous: <a href="Function-Call-Semantics.html" accesskey="p" rel="prev">Function Call Semantics</a>, Up: <a href="Functions.html" accesskey="u" rel="up">Functions</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Symbol-Index.html" title="Index" rel="index">Index</a>]</p>
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| 61 | </div>
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| 62 | <hr>
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| 63 | <span id="Function-Pointers-1"></span><h3 class="section">22.5 Function Pointers</h3>
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| 64 | <span id="index-function-pointers"></span>
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| 65 | <span id="index-pointers-to-functions"></span>
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| 66 |
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| 67 | <p>A function name refers to a fixed function. Sometimes it is useful to
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| 68 | call a function to be determined at run time; to do this, you can use
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| 69 | a <em>function pointer value</em> that points to the chosen function
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| 70 | (see <a href="Pointers.html">Pointers</a>).
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| 71 | </p>
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| 72 | <p>Pointer-to-function types can be used to declare variables and other
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| 73 | data, including array elements, structure fields, and union
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| 74 | alternatives. They can also be used for function arguments and return
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| 75 | values. These types have the peculiarity that they are never
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| 76 | converted automatically to <code>void *</code> or vice versa. However, you
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| 77 | can do that conversion with a cast.
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| 78 | </p>
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| 79 | <table class="menu" border="0" cellspacing="0">
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| 80 | <tr><td align="left" valign="top">• <a href="Declaring-Function-Pointers.html" accesskey="1">Declaring Function Pointers</a></td><td> </td><td align="left" valign="top">How to declare a pointer to a function.
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| 81 | </td></tr>
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| 82 | <tr><td align="left" valign="top">• <a href="Assigning-Function-Pointers.html" accesskey="2">Assigning Function Pointers</a></td><td> </td><td align="left" valign="top">How to assign values to function pointers.
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| 83 | </td></tr>
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| 84 | <tr><td align="left" valign="top">• <a href="Calling-Function-Pointers.html" accesskey="3">Calling Function Pointers</a></td><td> </td><td align="left" valign="top">How to call functions through pointers.
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| 85 | </td></tr>
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| 86 | </table>
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| 87 |
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| 88 |
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| 89 |
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| 90 |
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| 91 | </body>
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| 92 | </html>
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