1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Dynamic buffer requirements (version 2)</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="../../boost_asio.html" title="Boost.Asio"> 8<link rel="up" href="../reference.html" title="Reference"> 9<link rel="prev" href="DynamicBuffer_v1.html" title="Dynamic buffer requirements (version 1)"> 10<link rel="next" href="Endpoint.html" title="Endpoint requirements"> 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="DynamicBuffer_v1.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.html"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../boost_asio.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="Endpoint.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="boost_asio.reference.DynamicBuffer_v2"></a><a class="link" href="DynamicBuffer_v2.html" title="Dynamic buffer requirements (version 2)">Dynamic buffer 28 requirements (version 2)</a> 29</h3></div></div></div> 30<p> 31 A dynamic buffer encapsulates memory storage that may be automatically resized 32 as required. 33 </p> 34<p> 35 A dynamic buffer type <code class="computeroutput">X</code> shall satisfy the requirements of <code class="computeroutput">CopyConstructible</code> 36 (C++ Std, [copyconstructible]) types in addition to those listed below. 37 </p> 38<p> 39 In the table below, <code class="computeroutput">X</code> denotes a dynamic buffer class, <code class="computeroutput">x</code> 40 denotes a value of type <code class="computeroutput">X&</code>, <code class="computeroutput">x1</code> denotes values 41 of type <code class="computeroutput">const X&</code>, <code class="computeroutput">pos</code> and <code class="computeroutput">n</code> denote 42 values of type <code class="computeroutput">size_t</code>, and <code class="computeroutput">u</code> denotes an identifier. 43 </p> 44<div class="table"> 45<a name="boost_asio.reference.DynamicBuffer_v2.t0"></a><p class="title"><b>Table 10. DynamicBuffer_v2 requirements</b></p> 46<div class="table-contents"><table class="table" summary="DynamicBuffer_v2 requirements"> 47<colgroup> 48<col> 49<col> 50<col> 51</colgroup> 52<thead><tr> 53<th> 54 <p> 55 expression 56 </p> 57 </th> 58<th> 59 <p> 60 type 61 </p> 62 </th> 63<th> 64 <p> 65 assertion/note<br> pre/post-conditions 66 </p> 67 </th> 68</tr></thead> 69<tbody> 70<tr> 71<td> 72 <p> 73 <code class="computeroutput">X::const_buffers_type</code> 74 </p> 75 </td> 76<td> 77 <p> 78 type meeting <a class="link" href="ConstBufferSequence.html" title="Constant buffer sequence requirements">ConstBufferSequence</a> 79 requirements. 80 </p> 81 </td> 82<td> 83 <p> 84 This type represents the underlying memory as a sequence of @c 85 const_buffer objects. 86 </p> 87 </td> 88</tr> 89<tr> 90<td> 91 <p> 92 <code class="computeroutput">X::mutable_buffers_type</code> 93 </p> 94 </td> 95<td> 96 <p> 97 type meeting <a class="link" href="MutableBufferSequence.html" title="Mutable buffer sequence requirements">MutableBufferSequence</a> 98 requirements. 99 </p> 100 </td> 101<td> 102 <p> 103 This type represents the underlying memory as a sequence of @c 104 mutable_buffer objects. 105 </p> 106 </td> 107</tr> 108<tr> 109<td> 110 <p> 111 <code class="computeroutput">x1.size()</code> 112 </p> 113 </td> 114<td> 115 <p> 116 <code class="computeroutput">size_t</code> 117 </p> 118 </td> 119<td> 120 <p> 121 Returns the size, in bytes, of the underlying memory. 122 </p> 123 </td> 124</tr> 125<tr> 126<td> 127 <p> 128 <code class="computeroutput">x1.max_size()</code> 129 </p> 130 </td> 131<td> 132 <p> 133 <code class="computeroutput">size_t</code> 134 </p> 135 </td> 136<td> 137 <p> 138 Returns the permitted maximum size of the underlying memory. 139 </p> 140 </td> 141</tr> 142<tr> 143<td> 144 <p> 145 <code class="computeroutput">x1.capacity()</code> 146 </p> 147 </td> 148<td> 149 <p> 150 <code class="computeroutput">size_t</code> 151 </p> 152 </td> 153<td> 154 <p> 155 Returns the maximum size to which the underlying memory can grow 156 without requiring reallocation. 157 </p> 158 </td> 159</tr> 160<tr> 161<td> 162 <p> 163 <code class="computeroutput">x1.data(pos, n)</code> 164 </p> 165 </td> 166<td> 167 <p> 168 <code class="computeroutput">X::const_buffers_type</code> 169 </p> 170 </td> 171<td> 172 <p> 173 Returns a constant buffer sequence <code class="computeroutput">u</code> that represents 174 the underlying memory beginning at offset <code class="computeroutput">pos</code>, and 175 where <code class="computeroutput">buffer_size(u) <= n</code>. 176 </p> 177 </td> 178</tr> 179<tr> 180<td> 181 <p> 182 <code class="computeroutput">x.data(pos, n)</code> 183 </p> 184 </td> 185<td> 186 <p> 187 <code class="computeroutput">X::mutable_buffers_type</code> 188 </p> 189 </td> 190<td> 191 <p> 192 Returns a mutable buffer sequence <code class="computeroutput">u</code> that represents 193 the underlying memory beginning at offset <code class="computeroutput">pos</code>, and 194 where <code class="computeroutput">buffer_size(u) <= n</code>. 195 </p> 196 </td> 197</tr> 198<tr> 199<td> 200 <p> 201 <code class="computeroutput">x.grow(n)</code> 202 </p> 203 </td> 204<td> 205 </td> 206<td> 207 <p> 208 Requires: <code class="computeroutput">size() + n <= max_size()</code>.<br> <br> 209 Extends the underlying memory to accommodate <code class="computeroutput">n</code> additional 210 bytes at the end. The dynamic buffer reallocates memory as required. 211 All constant or mutable buffer sequences previously obtained using 212 <code class="computeroutput">data()</code> are invalidated.<br> <br> Throws: <code class="computeroutput">length_error</code> 213 if <code class="computeroutput">size() + n > max_size()</code>. 214 </p> 215 </td> 216</tr> 217<tr> 218<td> 219 <p> 220 <code class="computeroutput">x.shrink(n)</code> 221 </p> 222 </td> 223<td> 224 </td> 225<td> 226 <p> 227 Removes <code class="computeroutput">n</code> bytes from the end of the underlying memory. 228 If <code class="computeroutput">n</code> is greater than the size of the underlying memory, 229 the entire underlying memory is emptied. All constant or mutable 230 buffer sequences previously obtained using <code class="computeroutput">data()</code> 231 are invalidated. 232 </p> 233 </td> 234</tr> 235<tr> 236<td> 237 <p> 238 <code class="computeroutput">x.consume(n)</code> 239 </p> 240 </td> 241<td> 242 </td> 243<td> 244 <p> 245 Removes <code class="computeroutput">n</code> bytes from the beginning of the underlying 246 memory. If <code class="computeroutput">n</code> is greater than the size of the underlying 247 memory, the entire underlying memory is emptied. All constant or 248 mutable buffer sequences previously obtained using <code class="computeroutput">data()</code> 249 are invalidated. 250 </p> 251 </td> 252</tr> 253</tbody> 254</table></div> 255</div> 256<br class="table-break"> 257</div> 258<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 259<td align="left"></td> 260<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 261 Kohlhoff<p> 262 Distributed under the Boost Software License, Version 1.0. (See accompanying 263 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>) 264 </p> 265</div></td> 266</tr></table> 267<hr> 268<div class="spirit-nav"> 269<a accesskey="p" href="DynamicBuffer_v1.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.html"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../boost_asio.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="Endpoint.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 270</div> 271</body> 272</html> 273
