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<h1>apr_optional.h</h1> </div>
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<a href="apr__optional_8h.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/* Licensed to the Apache Software Foundation (ASF) under one or more</span>
<a name="l00002"></a>00002 <span class="comment"> * contributor license agreements. See the NOTICE file distributed with</span>
<a name="l00003"></a>00003 <span class="comment"> * this work for additional information regarding copyright ownership.</span>
<a name="l00004"></a>00004 <span class="comment"> * The ASF licenses this file to You under the Apache License, Version 2.0</span>
<a name="l00005"></a>00005 <span class="comment"> * (the "License"); you may not use this file except in compliance with</span>
<a name="l00006"></a>00006 <span class="comment"> * the License. You may obtain a copy of the License at</span>
<a name="l00007"></a>00007 <span class="comment"> *</span>
<a name="l00008"></a>00008 <span class="comment"> * http://www.apache.org/licenses/LICENSE-2.0</span>
<a name="l00009"></a>00009 <span class="comment"> *</span>
<a name="l00010"></a>00010 <span class="comment"> * Unless required by applicable law or agreed to in writing, software</span>
<a name="l00011"></a>00011 <span class="comment"> * distributed under the License is distributed on an "AS IS" BASIS,</span>
<a name="l00012"></a>00012 <span class="comment"> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.</span>
<a name="l00013"></a>00013 <span class="comment"> * See the License for the specific language governing permissions and</span>
<a name="l00014"></a>00014 <span class="comment"> * limitations under the License.</span>
<a name="l00015"></a>00015 <span class="comment"> */</span>
<a name="l00016"></a>00016
<a name="l00017"></a>00017 <span class="preprocessor">#ifndef APR_OPTIONAL_H</span>
<a name="l00018"></a>00018 <span class="preprocessor"></span><span class="preprocessor">#define APR_OPTIONAL_H</span>
<a name="l00019"></a>00019 <span class="preprocessor"></span>
<a name="l00020"></a>00020 <span class="preprocessor">#include "apu.h"</span><span class="comment"></span>
<a name="l00021"></a>00021 <span class="comment">/** </span>
<a name="l00022"></a>00022 <span class="comment"> * @file apr_optional.h</span>
<a name="l00023"></a>00023 <span class="comment"> * @brief APR-UTIL registration of functions exported by modules</span>
<a name="l00024"></a>00024 <span class="comment"> */</span>
<a name="l00025"></a>00025 <span class="preprocessor">#ifdef __cplusplus</span>
<a name="l00026"></a>00026 <span class="preprocessor"></span><span class="keyword">extern</span> <span class="stringliteral">"C"</span> {
<a name="l00027"></a>00027 <span class="preprocessor">#endif</span>
<a name="l00028"></a>00028 <span class="preprocessor"></span><span class="comment"></span>
<a name="l00029"></a>00029 <span class="comment">/** </span>
<a name="l00030"></a>00030 <span class="comment"> * @defgroup APR_Util_Opt Optional Functions</span>
<a name="l00031"></a>00031 <span class="comment"> * @ingroup APR_Util</span>
<a name="l00032"></a>00032 <span class="comment"> *</span>
<a name="l00033"></a>00033 <span class="comment"> * Typesafe registration and retrieval of functions that may not be present</span>
<a name="l00034"></a>00034 <span class="comment"> * (i.e. functions exported by optional modules)</span>
<a name="l00035"></a>00035 <span class="comment"> * @{</span>
<a name="l00036"></a>00036 <span class="comment"> */</span>
<a name="l00037"></a>00037 <span class="comment"></span>
<a name="l00038"></a>00038 <span class="comment">/**</span>
<a name="l00039"></a>00039 <span class="comment"> * The type of an optional function.</span>
<a name="l00040"></a>00040 <span class="comment"> * @param name The name of the function</span>
<a name="l00041"></a>00041 <span class="comment"> */</span>
<a name="l00042"></a><a class="code" href="group___a_p_r___util___opt.html#ga987fcf75505450f1b4ff9d7b3a7ff5d3">00042</a> <span class="preprocessor">#define APR_OPTIONAL_FN_TYPE(name) apr_OFN_##name##_t</span>
<a name="l00043"></a>00043 <span class="preprocessor"></span><span class="comment"></span>
<a name="l00044"></a>00044 <span class="comment">/**</span>
<a name="l00045"></a>00045 <span class="comment"> * Declare an optional function.</span>
<a name="l00046"></a>00046 <span class="comment"> * @param ret The return type of the function</span>
<a name="l00047"></a>00047 <span class="comment"> * @param name The name of the function</span>
<a name="l00048"></a>00048 <span class="comment"> * @param args The function arguments (including brackets)</span>
<a name="l00049"></a>00049 <span class="comment"> */</span>
<a name="l00050"></a><a class="code" href="group___a_p_r___util___opt.html#gaf3ff372e28978d4ce0be7517ca2fddbd">00050</a> <span class="preprocessor">#define APR_DECLARE_OPTIONAL_FN(ret,name,args) \</span>
<a name="l00051"></a>00051 <span class="preprocessor">typedef ret (APR_OPTIONAL_FN_TYPE(name)) args</span>
<a name="l00052"></a>00052 <span class="preprocessor"></span><span class="comment"></span>
<a name="l00053"></a>00053 <span class="comment">/**</span>
<a name="l00054"></a>00054 <span class="comment"> * XXX: This doesn't belong here, then!</span>
<a name="l00055"></a>00055 <span class="comment"> * Private function! DO NOT USE! </span>
<a name="l00056"></a>00056 <span class="comment"> * @internal</span>
<a name="l00057"></a>00057 <span class="comment"> */</span>
<a name="l00058"></a>00058
<a name="l00059"></a><a class="code" href="group___a_p_r___util___opt.html#ga35e08c2dbf593e3dc5a2cb0fdc8cd637">00059</a> <span class="keyword">typedef</span> void (<a class="code" href="group___a_p_r___util___opt.html#ga35e08c2dbf593e3dc5a2cb0fdc8cd637">apr_opt_fn_t</a>)(void);<span class="comment"></span>
<a name="l00060"></a>00060 <span class="comment">/** @internal */</span>
<a name="l00061"></a>00061 APU_DECLARE_NONSTD(<span class="keywordtype">void</span>) apr_dynamic_fn_register(const <span class="keywordtype">char</span> *szName,
<a name="l00062"></a>00062 <a class="code" href="group___a_p_r___util___opt.html#ga35e08c2dbf593e3dc5a2cb0fdc8cd637">apr_opt_fn_t</a> *pfn);
<a name="l00063"></a>00063 <span class="comment"></span>
<a name="l00064"></a>00064 <span class="comment">/**</span>
<a name="l00065"></a>00065 <span class="comment"> * Register an optional function. This can be later retrieved, type-safely, by</span>
<a name="l00066"></a>00066 <span class="comment"> * name. Like all global functions, the name must be unique. Note that,</span>
<a name="l00067"></a>00067 <span class="comment"> * confusingly but correctly, the function itself can be static!</span>
<a name="l00068"></a>00068 <span class="comment"> * @param name The name of the function</span>
<a name="l00069"></a>00069 <span class="comment"> */</span>
<a name="l00070"></a><a class="code" href="group___a_p_r___util___opt.html#gab611deabd6e78b5f666071e8cbdcc736">00070</a> <span class="preprocessor">#define APR_REGISTER_OPTIONAL_FN(name) do { \</span>
<a name="l00071"></a>00071 <span class="preprocessor"> APR_OPTIONAL_FN_TYPE(name) *apu__opt = name; \</span>
<a name="l00072"></a>00072 <span class="preprocessor"> apr_dynamic_fn_register(#name,(apr_opt_fn_t *)apu__opt); \</span>
<a name="l00073"></a>00073 <span class="preprocessor">} while (0)</span>
<a name="l00074"></a>00074 <span class="preprocessor"></span><span class="comment"></span>
<a name="l00075"></a>00075 <span class="comment">/** @internal</span>
<a name="l00076"></a>00076 <span class="comment"> * Private function! DO NOT USE! </span>
<a name="l00077"></a>00077 <span class="comment"> */</span>
<a name="l00078"></a>00078 APU_DECLARE(<a class="code" href="group___a_p_r___util___opt.html#ga35e08c2dbf593e3dc5a2cb0fdc8cd637">apr_opt_fn_t</a> *) apr_dynamic_fn_retrieve(const <span class="keywordtype">char</span> *szName);
<a name="l00079"></a>00079 <span class="comment"></span>
<a name="l00080"></a>00080 <span class="comment">/**</span>
<a name="l00081"></a>00081 <span class="comment"> * Retrieve an optional function. Returns NULL if the function is not present.</span>
<a name="l00082"></a>00082 <span class="comment"> * @param name The name of the function</span>
<a name="l00083"></a>00083 <span class="comment"> */</span>
<a name="l00084"></a><a class="code" href="group___a_p_r___util___opt.html#ga35f2df25ca06248d2fdd3e7463446418">00084</a> <span class="preprocessor">#define APR_RETRIEVE_OPTIONAL_FN(name) \</span>
<a name="l00085"></a>00085 <span class="preprocessor"> (APR_OPTIONAL_FN_TYPE(name) *)apr_dynamic_fn_retrieve(#name)</span>
<a name="l00086"></a>00086 <span class="preprocessor"></span><span class="comment"></span>
<a name="l00087"></a>00087 <span class="comment">/** @} */</span>
<a name="l00088"></a>00088 <span class="preprocessor">#ifdef __cplusplus</span>
<a name="l00089"></a>00089 <span class="preprocessor"></span>}
<a name="l00090"></a>00090 <span class="preprocessor">#endif</span>
<a name="l00091"></a>00091 <span class="preprocessor"></span>
<a name="l00092"></a>00092 <span class="preprocessor">#endif </span><span class="comment">/* APR_OPTIONAL_H */</span>
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