1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Body</title> 5<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../index.html" title="Chapter 1. Boost.Beast"> 8<link rel="up" href="../concepts.html" title="Concepts"> 9<link rel="prev" href="../concepts.html" title="Concepts"> 10<link rel="next" href="BodyReader.html" title="BodyReader"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="../concepts.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../concepts.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="BodyReader.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h3 class="title"> 27<a name="beast.concepts.Body"></a><a class="link" href="Body.html" title="Body">Body</a> 28</h3></div></div></div> 29<p> 30 A <span class="bold"><strong>Body</strong></span> type is supplied as a template argument 31 to the <a class="link" href="../ref/boost__beast__http__message.html" title="http::message"><code class="computeroutput"><span class="identifier">message</span></code></a> class. It controls both 32 the type of the data member of the resulting message object, and the algorithms 33 used during parsing and serialization. 34 </p> 35<h5> 36<a name="beast.concepts.Body.h0"></a> 37 <span class="phrase"><a name="beast.concepts.Body.associated_types"></a></span><a class="link" href="Body.html#beast.concepts.Body.associated_types">Associated 38 Types</a> 39 </h5> 40<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 41<li class="listitem"> 42 <a class="link" href="../ref/boost__beast__http__is_body.html" title="http::is_body"><code class="computeroutput"><span class="identifier">is_body</span></code></a> 43 </li> 44<li class="listitem"> 45 <a class="link" href="BodyReader.html" title="BodyReader"><span class="emphasis"><em>BodyReader</em></span></a> 46 </li> 47<li class="listitem"> 48 <a class="link" href="BodyWriter.html" title="BodyWriter"><span class="emphasis"><em>BodyWriter</em></span></a> 49 </li> 50</ul></div> 51<h5> 52<a name="beast.concepts.Body.h1"></a> 53 <span class="phrase"><a name="beast.concepts.Body.requirements"></a></span><a class="link" href="Body.html#beast.concepts.Body.requirements">Requirements</a> 54 </h5> 55<p> 56 In this table: 57 </p> 58<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 59<li class="listitem"> 60 <code class="computeroutput"><span class="identifier">B</span></code> is a type meeting the 61 requirements of <span class="bold"><strong>Body</strong></span>. 62 </li> 63<li class="listitem"> 64 <code class="computeroutput"><span class="identifier">m</span></code> is a value of type 65 <code class="computeroutput"><span class="identifier">message</span><span class="special"><</span><span class="identifier">b</span><span class="special">,</span><span class="identifier">B</span><span class="special">,</span><span class="identifier">F</span><span class="special">></span></code> 66 where <code class="computeroutput"><span class="identifier">b</span></code> is a <code class="computeroutput"><span class="keyword">bool</span></code> value and <code class="computeroutput"><span class="identifier">F</span></code> 67 is a type meeting the requirements of <a class="link" href="Fields.html" title="Fields"><span class="emphasis"><em>Fields</em></span></a>. 68 </li> 69</ul></div> 70<div class="table"> 71<a name="beast.concepts.Body.valid_expressions"></a><p class="title"><b>Table 1.37. Valid expressions</b></p> 72<div class="table-contents"><table class="table" summary="Valid expressions"> 73<colgroup> 74<col> 75<col> 76<col> 77</colgroup> 78<thead><tr> 79<th> 80 <p> 81 Expression 82 </p> 83 </th> 84<th> 85 <p> 86 Type 87 </p> 88 </th> 89<th> 90 <p> 91 Semantics, Pre/Post-conditions 92 </p> 93 </th> 94</tr></thead> 95<tbody> 96<tr> 97<td> 98 <p> 99 <code class="computeroutput"><span class="identifier">B</span><span class="special">::</span><span class="identifier">value_type</span></code> 100 </p> 101 </td> 102<td> 103 </td> 104<td> 105 <p> 106 The return type of the <code class="computeroutput"><span class="identifier">message</span><span class="special">::</span><span class="identifier">body</span></code> 107 member function. If this is not movable or not copyable, the containing 108 message will be not movable or not copyable. 109 </p> 110 </td> 111</tr> 112<tr> 113<td> 114 <p> 115 <code class="computeroutput"><span class="identifier">B</span><span class="special">::</span><span class="identifier">reader</span></code> 116 </p> 117 </td> 118<td> 119 </td> 120<td> 121 <p> 122 If present, indicates that the body can be parsed. The type must 123 meet the requirements of <a class="link" href="BodyReader.html" title="BodyReader"><span class="emphasis"><em>BodyReader</em></span></a>. 124 The implementation constructs an object of this type to obtain 125 buffers into which parsed body octets are placed. 126 </p> 127 </td> 128</tr> 129<tr> 130<td> 131 <p> 132 <code class="computeroutput"><span class="identifier">B</span><span class="special">::</span><span class="identifier">writer</span></code> 133 </p> 134 </td> 135<td> 136 </td> 137<td> 138 <p> 139 If present, indicates that the body is serializable. The type must 140 meet the requirements of <a class="link" href="BodyWriter.html" title="BodyWriter"><span class="emphasis"><em>BodyWriter</em></span></a>. 141 The implementation constructs an object of this type to obtain 142 buffers representing the message body for serialization. 143 </p> 144 </td> 145</tr> 146<tr> 147<td> 148<pre class="programlisting"><span class="identifier">B</span><span class="special">::</span><span class="identifier">size</span><span class="special">(</span> 149 <span class="identifier">B</span><span class="special">::</span><span class="identifier">value_type</span> <span class="identifier">body</span><span class="special">)</span> 150</pre> 151 </td> 152<td> 153 <p> 154 <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">uint64_t</span></code> 155 </p> 156 </td> 157<td> 158 <p> 159 This static member function is optional. It returns the payload 160 size of <code class="computeroutput"><span class="identifier">body</span></code> in 161 bytes not including any chunked transfer encoding. The return value 162 may be zero, to indicate that the message is known to have no payload. 163 The function shall not exit via an exception. 164 </p> 165 <p> 166 When this function is present: 167 </p> 168 <p> 169 * The function shall not fail 170 </p> 171 <p> 172 * A call to <a class="link" href="../ref/boost__beast__http__message/payload_size.html" title="http::message::payload_size"><code class="computeroutput"><span class="identifier">message</span><span class="special">::</span><span class="identifier">payload_size</span></code></a> will return 173 the same value as <code class="computeroutput"><span class="identifier">size</span></code>. 174 </p> 175 <p> 176 * A call to <a class="link" href="../ref/boost__beast__http__message/prepare_payload.html" title="http::message::prepare_payload"><code class="computeroutput"><span class="identifier">message</span><span class="special">::</span><span class="identifier">prepare_payload</span></code></a> will remove 177 "chunked" from the Transfer-Encoding field if it appears 178 as the last encoding, and will set the Content-Length field to 179 the returned value. 180 </p> 181 <p> 182 Otherwise, when the function is omitted: 183 </p> 184 <p> 185 * A call to <a class="link" href="../ref/boost__beast__http__message/payload_size.html" title="http::message::payload_size"><code class="computeroutput"><span class="identifier">message</span><span class="special">::</span><span class="identifier">payload_size</span></code></a> will return 186 <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">none</span></code>. 187 </p> 188 <p> 189 * A call to <a class="link" href="../ref/boost__beast__http__message/prepare_payload.html" title="http::message::prepare_payload"><code class="computeroutput"><span class="identifier">message</span><span class="special">::</span><span class="identifier">prepare_payload</span></code></a> will erase 190 the Content-Length field, and add "chunked" as the last 191 encoding in the Transfer-Encoding field if it is not already present. 192 </p> 193 </td> 194</tr> 195</tbody> 196</table></div> 197</div> 198<br class="table-break"><h5> 199<a name="beast.concepts.Body.h2"></a> 200 <span class="phrase"><a name="beast.concepts.Body.exemplar"></a></span><a class="link" href="Body.html#beast.concepts.Body.exemplar">Exemplar</a> 201 </h5> 202<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">Body</span> 203<span class="special">{</span> 204 <span class="comment">// The type of message::body when used</span> 205 <span class="keyword">struct</span> <span class="identifier">value_type</span><span class="special">;</span> 206 207 <span class="comment">/// The algorithm used during parsing</span> 208 <span class="keyword">class</span> <span class="identifier">reader</span><span class="special">;</span> 209 210 <span class="comment">/// The algorithm used during serialization</span> 211 <span class="keyword">class</span> <span class="identifier">writer</span><span class="special">;</span> 212 213 <span class="comment">/// Returns the body's payload size</span> 214 <span class="keyword">static</span> 215 <span class="identifier">std</span><span class="special">::</span><span class="identifier">uint64_t</span> 216 <span class="identifier">size</span><span class="special">(</span><span class="identifier">value_type</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">body</span><span class="special">);</span> 217<span class="special">};</span> 218 219<span class="keyword">static_assert</span><span class="special">(</span><span class="identifier">is_body</span><span class="special"><</span><span class="identifier">Body</span><span class="special">>::</span><span class="identifier">value</span><span class="special">,</span> <span class="string">""</span><span class="special">);</span> 220</pre> 221<h5> 222<a name="beast.concepts.Body.h3"></a> 223 <span class="phrase"><a name="beast.concepts.Body.models"></a></span><a class="link" href="Body.html#beast.concepts.Body.models">Models</a> 224 </h5> 225<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 226<li class="listitem"> 227 <a class="link" href="../ref/boost__beast__http__basic_dynamic_body.html" title="http::basic_dynamic_body"><code class="computeroutput"><span class="identifier">basic_dynamic_body</span></code></a> 228 </li> 229<li class="listitem"> 230 <a class="link" href="../ref/boost__beast__http__basic_file_body.html" title="http::basic_file_body"><code class="computeroutput"><span class="identifier">basic_file_body</span></code></a> 231 </li> 232<li class="listitem"> 233 <a class="link" href="../ref/boost__beast__http__basic_string_body.html" title="http::basic_string_body"><code class="computeroutput"><span class="identifier">basic_string_body</span></code></a> 234 </li> 235<li class="listitem"> 236 <a class="link" href="../ref/boost__beast__http__buffer_body.html" title="http::buffer_body"><code class="computeroutput"><span class="identifier">buffer_body</span></code></a> 237 </li> 238<li class="listitem"> 239 <a class="link" href="../ref/boost__beast__http__empty_body.html" title="http::empty_body"><code class="computeroutput"><span class="identifier">empty_body</span></code></a> 240 </li> 241<li class="listitem"> 242 <a class="link" href="../ref/boost__beast__http__span_body.html" title="http::span_body"><code class="computeroutput"><span class="identifier">span_body</span></code></a> 243 </li> 244<li class="listitem"> 245 <a class="link" href="../ref/boost__beast__http__vector_body.html" title="http::vector_body"><code class="computeroutput"><span class="identifier">vector_body</span></code></a> 246 </li> 247</ul></div> 248</div> 249<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 250<td align="left"></td> 251<td align="right"><div class="copyright-footer">Copyright © 2016-2019 Vinnie 252 Falco<p> 253 Distributed under the Boost Software License, Version 1.0. (See accompanying 254 file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 255 </p> 256</div></td> 257</tr></table> 258<hr> 259<div class="spirit-nav"> 260<a accesskey="p" href="../concepts.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../concepts.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="BodyReader.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 261</div> 262</body> 263</html> 264
