<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Dynamic buffer requirements (version 2)</title>
<link rel="stylesheet" href="../../boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
<link rel="home" href="../../index.html" title="Asio">
<link rel="up" href="../reference.html" title="Reference">
<link rel="prev" href="DynamicBuffer_v1.html" title="Dynamic buffer requirements (version 1)">
<link rel="next" href="Endpoint.html" title="Endpoint requirements">
<meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr><td valign="top"><img alt="asio C++ library" width="250" height="60" src="../../asio.png"></td></tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="DynamicBuffer_v1.html"><img src="../../prev.png" alt="Prev"></a><a accesskey="u" href="../reference.html"><img src="../../up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../home.png" alt="Home"></a><a accesskey="n" href="Endpoint.html"><img src="../../next.png" alt="Next"></a>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="asio.reference.DynamicBuffer_v2"></a><a class="link" href="DynamicBuffer_v2.html" title="Dynamic buffer requirements (version 2)">Dynamic buffer requirements
(version 2)</a>
</h3></div></div></div>
<p>
A dynamic buffer encapsulates memory storage that may be automatically resized
as required.
</p>
<p>
A dynamic buffer type <code class="computeroutput"><span class="identifier">X</span></code> shall
satisfy the requirements of <code class="computeroutput"><span class="identifier">CopyConstructible</span></code>
(C++ Std, [copyconstructible]) types in addition to those listed below.
</p>
<p>
In the table below, <code class="computeroutput"><span class="identifier">X</span></code> denotes
a dynamic buffer class, <code class="computeroutput"><span class="identifier">x</span></code>
denotes a value of type <code class="computeroutput"><span class="identifier">X</span><span class="special">&</span></code>, <code class="computeroutput"><span class="identifier">x1</span></code>
denotes values of type <code class="computeroutput"><span class="keyword">const</span> <span class="identifier">X</span><span class="special">&</span></code>,
<code class="computeroutput"><span class="identifier">pos</span></code> and <code class="computeroutput"><span class="identifier">n</span></code>
denote values of type <code class="computeroutput"><span class="identifier">size_t</span></code>,
and <code class="computeroutput"><span class="identifier">u</span></code> denotes an identifier.
</p>
<div class="table">
<a name="asio.reference.DynamicBuffer_v2.t0"></a><p class="title"><b>Table 13. DynamicBuffer_v2 requirements</b></p>
<div class="table-contents"><table class="table" summary="DynamicBuffer_v2 requirements">
<colgroup>
<col>
<col>
<col>
</colgroup>
<thead><tr>
<th>
<p>
expression
</p>
</th>
<th>
<p>
type
</p>
</th>
<th>
<p>
assertion/note<br> pre/post-conditions
</p>
</th>
</tr></thead>
<tbody>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">X</span><span class="special">::</span><span class="identifier">const_buffers_type</span></code>
</p>
</td>
<td>
<p>
type meeting <a class="link" href="ConstBufferSequence.html" title="Constant buffer sequence requirements">ConstBufferSequence</a>
requirements.
</p>
</td>
<td>
<p>
This type represents the underlying memory as a sequence of @c
const_buffer objects.
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">X</span><span class="special">::</span><span class="identifier">mutable_buffers_type</span></code>
</p>
</td>
<td>
<p>
type meeting <a class="link" href="MutableBufferSequence.html" title="Mutable buffer sequence requirements">MutableBufferSequence</a>
requirements.
</p>
</td>
<td>
<p>
This type represents the underlying memory as a sequence of @c
mutable_buffer objects.
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">x1</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span></code>
</p>
</td>
<td>
<p>
<code class="computeroutput"><span class="identifier">size_t</span></code>
</p>
</td>
<td>
<p>
Returns the size, in bytes, of the underlying memory.
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">x1</span><span class="special">.</span><span class="identifier">max_size</span><span class="special">()</span></code>
</p>
</td>
<td>
<p>
<code class="computeroutput"><span class="identifier">size_t</span></code>
</p>
</td>
<td>
<p>
Returns the permitted maximum size of the underlying memory.
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">x1</span><span class="special">.</span><span class="identifier">capacity</span><span class="special">()</span></code>
</p>
</td>
<td>
<p>
<code class="computeroutput"><span class="identifier">size_t</span></code>
</p>
</td>
<td>
<p>
Returns the maximum size to which the underlying memory can grow
without requiring reallocation.
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">x1</span><span class="special">.</span><span class="identifier">data</span><span class="special">(</span><span class="identifier">pos</span><span class="special">,</span>
<span class="identifier">n</span><span class="special">)</span></code>
</p>
</td>
<td>
<p>
<code class="computeroutput"><span class="identifier">X</span><span class="special">::</span><span class="identifier">const_buffers_type</span></code>
</p>
</td>
<td>
<p>
Returns a constant buffer sequence <code class="computeroutput"><span class="identifier">u</span></code>
that represents the underlying memory beginning at offset <code class="computeroutput"><span class="identifier">pos</span></code>, and where <code class="computeroutput"><span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">u</span><span class="special">)</span>
<span class="special"><=</span> <span class="identifier">n</span></code>.
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">x</span><span class="special">.</span><span class="identifier">data</span><span class="special">(</span><span class="identifier">pos</span><span class="special">,</span>
<span class="identifier">n</span><span class="special">)</span></code>
</p>
</td>
<td>
<p>
<code class="computeroutput"><span class="identifier">X</span><span class="special">::</span><span class="identifier">mutable_buffers_type</span></code>
</p>
</td>
<td>
<p>
Returns a mutable buffer sequence <code class="computeroutput"><span class="identifier">u</span></code>
that represents the underlying memory beginning at offset <code class="computeroutput"><span class="identifier">pos</span></code>, and where <code class="computeroutput"><span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">u</span><span class="special">)</span>
<span class="special"><=</span> <span class="identifier">n</span></code>.
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">x</span><span class="special">.</span><span class="identifier">grow</span><span class="special">(</span><span class="identifier">n</span><span class="special">)</span></code>
</p>
</td>
<td>
</td>
<td>
<p>
Requires: <code class="computeroutput"><span class="identifier">size</span><span class="special">()</span> <span class="special">+</span> <span class="identifier">n</span> <span class="special"><=</span>
<span class="identifier">max_size</span><span class="special">()</span></code>.<br>
<br> Extends the underlying memory to accommodate <code class="computeroutput"><span class="identifier">n</span></code> additional bytes at the end.
The dynamic buffer reallocates memory as required. All constant
or mutable buffer sequences previously obtained using <code class="computeroutput"><span class="identifier">data</span><span class="special">()</span></code>
are invalidated.<br> <br> Throws: <code class="computeroutput"><span class="identifier">length_error</span></code>
if <code class="computeroutput"><span class="identifier">size</span><span class="special">()</span>
<span class="special">+</span> <span class="identifier">n</span>
<span class="special">></span> <span class="identifier">max_size</span><span class="special">()</span></code>.
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">x</span><span class="special">.</span><span class="identifier">shrink</span><span class="special">(</span><span class="identifier">n</span><span class="special">)</span></code>
</p>
</td>
<td>
</td>
<td>
<p>
Removes <code class="computeroutput"><span class="identifier">n</span></code> bytes
from the end of the underlying memory. If <code class="computeroutput"><span class="identifier">n</span></code>
is greater than the size of the underlying memory, the entire underlying
memory is emptied. All constant or mutable buffer sequences previously
obtained using <code class="computeroutput"><span class="identifier">data</span><span class="special">()</span></code> are invalidated.
</p>
</td>
</tr>
<tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">x</span><span class="special">.</span><span class="identifier">consume</span><span class="special">(</span><span class="identifier">n</span><span class="special">)</span></code>
</p>
</td>
<td>
</td>
<td>
<p>
Removes <code class="computeroutput"><span class="identifier">n</span></code> bytes
from the beginning of the underlying memory. If <code class="computeroutput"><span class="identifier">n</span></code>
is greater than the size of the underlying memory, the entire underlying
memory is emptied. All constant or mutable buffer sequences previously
obtained using <code class="computeroutput"><span class="identifier">data</span><span class="special">()</span></code> are invalidated.
</p>
</td>
</tr>
</tbody>
</table></div>
</div>
<br class="table-break">
</div>
<div class="copyright-footer">Copyright © 2003-2023 Christopher M. Kohlhoff<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
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>)
</p>
</div>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="DynamicBuffer_v1.html"><img src="../../prev.png" alt="Prev"></a><a accesskey="u" href="../reference.html"><img src="../../up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../home.png" alt="Home"></a><a accesskey="n" href="Endpoint.html"><img src="../../next.png" alt="Next"></a>
</div>
</body>
</html>