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<a name="asio.reference.buffer"></a><a class="link" href="buffer.html" title="buffer">buffer</a>
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<p>
        <a class="indexterm" name="idp121284608"></a> 
The <code class="computeroutput"><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span></code> function is used to create a buffer
        object to represent raw memory, an array of POD elements, a vector of POD
        elements, or a std::string.
      </p>
<pre class="programlisting"><span class="identifier">mutable_buffers_1</span> <a class="link" href="buffer/overload1.html" title="buffer (1 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="keyword">const</span> <span class="identifier">mutable_buffer</span> <span class="special">&amp;</span> <span class="identifier">b</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload1.html" title="buffer (1 of 28 overloads)">more...</a></em></span>

<span class="identifier">mutable_buffers_1</span> <a class="link" href="buffer/overload2.html" title="buffer (2 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="keyword">const</span> <span class="identifier">mutable_buffer</span> <span class="special">&amp;</span> <span class="identifier">b</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_size_in_bytes</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload2.html" title="buffer (2 of 28 overloads)">more...</a></em></span>

<span class="identifier">const_buffers_1</span> <a class="link" href="buffer/overload3.html" title="buffer (3 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="keyword">const</span> <span class="identifier">const_buffer</span> <span class="special">&amp;</span> <span class="identifier">b</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload3.html" title="buffer (3 of 28 overloads)">more...</a></em></span>

<span class="identifier">const_buffers_1</span> <a class="link" href="buffer/overload4.html" title="buffer (4 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="keyword">const</span> <span class="identifier">const_buffer</span> <span class="special">&amp;</span> <span class="identifier">b</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_size_in_bytes</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload4.html" title="buffer (4 of 28 overloads)">more...</a></em></span>

<span class="identifier">mutable_buffers_1</span> <a class="link" href="buffer/overload5.html" title="buffer (5 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="keyword">void</span> <span class="special">*</span> <span class="identifier">data</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size_in_bytes</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload5.html" title="buffer (5 of 28 overloads)">more...</a></em></span>

<span class="identifier">const_buffers_1</span> <a class="link" href="buffer/overload6.html" title="buffer (6 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="keyword">const</span> <span class="keyword">void</span> <span class="special">*</span> <span class="identifier">data</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size_in_bytes</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload6.html" title="buffer (6 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span><span class="special">&gt;</span>
<span class="identifier">mutable_buffers_1</span> <a class="link" href="buffer/overload7.html" title="buffer (7 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="identifier">PodType</span> <span class="special">(&amp;</span><span class="identifier">data</span><span class="special">)[</span><span class="identifier">N</span><span class="special">]);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload7.html" title="buffer (7 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span><span class="special">&gt;</span>
<span class="identifier">mutable_buffers_1</span> <a class="link" href="buffer/overload8.html" title="buffer (8 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="identifier">PodType</span> <span class="special">(&amp;</span><span class="identifier">data</span><span class="special">)[</span><span class="identifier">N</span><span class="special">],</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_size_in_bytes</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload8.html" title="buffer (8 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span><span class="special">&gt;</span>
<span class="identifier">const_buffers_1</span> <a class="link" href="buffer/overload9.html" title="buffer (9 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="keyword">const</span> <span class="identifier">PodType</span> <span class="special">(&amp;</span><span class="identifier">data</span><span class="special">)[</span><span class="identifier">N</span><span class="special">]);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload9.html" title="buffer (9 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span><span class="special">&gt;</span>
<span class="identifier">const_buffers_1</span> <a class="link" href="buffer/overload10.html" title="buffer (10 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="keyword">const</span> <span class="identifier">PodType</span> <span class="special">(&amp;</span><span class="identifier">data</span><span class="special">)[</span><span class="identifier">N</span><span class="special">],</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_size_in_bytes</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload10.html" title="buffer (10 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span><span class="special">&gt;</span>
<span class="identifier">mutable_buffers_1</span> <a class="link" href="buffer/overload11.html" title="buffer (11 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span> <span class="identifier">PodType</span><span class="special">,</span> <span class="identifier">N</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload11.html" title="buffer (11 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span><span class="special">&gt;</span>
<span class="identifier">mutable_buffers_1</span> <a class="link" href="buffer/overload12.html" title="buffer (12 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span> <span class="identifier">PodType</span><span class="special">,</span> <span class="identifier">N</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_size_in_bytes</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload12.html" title="buffer (12 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span><span class="special">&gt;</span>
<span class="identifier">const_buffers_1</span> <a class="link" href="buffer/overload13.html" title="buffer (13 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span> <span class="keyword">const</span> <span class="identifier">PodType</span><span class="special">,</span> <span class="identifier">N</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload13.html" title="buffer (13 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span><span class="special">&gt;</span>
<span class="identifier">const_buffers_1</span> <a class="link" href="buffer/overload14.html" title="buffer (14 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span> <span class="keyword">const</span> <span class="identifier">PodType</span><span class="special">,</span> <span class="identifier">N</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_size_in_bytes</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload14.html" title="buffer (14 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span><span class="special">&gt;</span>
<span class="identifier">const_buffers_1</span> <a class="link" href="buffer/overload15.html" title="buffer (15 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span> <span class="identifier">PodType</span><span class="special">,</span> <span class="identifier">N</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload15.html" title="buffer (15 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span><span class="special">&gt;</span>
<span class="identifier">const_buffers_1</span> <a class="link" href="buffer/overload16.html" title="buffer (16 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span> <span class="identifier">PodType</span><span class="special">,</span> <span class="identifier">N</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_size_in_bytes</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload16.html" title="buffer (16 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span><span class="special">&gt;</span>
<span class="identifier">mutable_buffers_1</span> <a class="link" href="buffer/overload17.html" title="buffer (17 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span> <span class="identifier">PodType</span><span class="special">,</span> <span class="identifier">N</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload17.html" title="buffer (17 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span><span class="special">&gt;</span>
<span class="identifier">mutable_buffers_1</span> <a class="link" href="buffer/overload18.html" title="buffer (18 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span> <span class="identifier">PodType</span><span class="special">,</span> <span class="identifier">N</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_size_in_bytes</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload18.html" title="buffer (18 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span><span class="special">&gt;</span>
<span class="identifier">const_buffers_1</span> <a class="link" href="buffer/overload19.html" title="buffer (19 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span> <span class="keyword">const</span> <span class="identifier">PodType</span><span class="special">,</span> <span class="identifier">N</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload19.html" title="buffer (19 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span><span class="special">&gt;</span>
<span class="identifier">const_buffers_1</span> <a class="link" href="buffer/overload20.html" title="buffer (20 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span> <span class="keyword">const</span> <span class="identifier">PodType</span><span class="special">,</span> <span class="identifier">N</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_size_in_bytes</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload20.html" title="buffer (20 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span><span class="special">&gt;</span>
<span class="identifier">const_buffers_1</span> <a class="link" href="buffer/overload21.html" title="buffer (21 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span> <span class="identifier">PodType</span><span class="special">,</span> <span class="identifier">N</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload21.html" title="buffer (21 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span><span class="special">&gt;</span>
<span class="identifier">const_buffers_1</span> <a class="link" href="buffer/overload22.html" title="buffer (22 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span> <span class="identifier">PodType</span><span class="special">,</span> <span class="identifier">N</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_size_in_bytes</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload22.html" title="buffer (22 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="keyword">typename</span> <span class="identifier">Allocator</span><span class="special">&gt;</span>
<span class="identifier">mutable_buffers_1</span> <a class="link" href="buffer/overload23.html" title="buffer (23 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span> <span class="identifier">PodType</span><span class="special">,</span> <span class="identifier">Allocator</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload23.html" title="buffer (23 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="keyword">typename</span> <span class="identifier">Allocator</span><span class="special">&gt;</span>
<span class="identifier">mutable_buffers_1</span> <a class="link" href="buffer/overload24.html" title="buffer (24 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span> <span class="identifier">PodType</span><span class="special">,</span> <span class="identifier">Allocator</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_size_in_bytes</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload24.html" title="buffer (24 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="keyword">typename</span> <span class="identifier">Allocator</span><span class="special">&gt;</span>
<span class="identifier">const_buffers_1</span> <a class="link" href="buffer/overload25.html" title="buffer (25 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span> <span class="identifier">PodType</span><span class="special">,</span> <span class="identifier">Allocator</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload25.html" title="buffer (25 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">PodType</span><span class="special">,</span>
    <span class="keyword">typename</span> <span class="identifier">Allocator</span><span class="special">&gt;</span>
<span class="identifier">const_buffers_1</span> <a class="link" href="buffer/overload26.html" title="buffer (26 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span> <span class="identifier">PodType</span><span class="special">,</span> <span class="identifier">Allocator</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_size_in_bytes</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload26.html" title="buffer (26 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">Elem</span><span class="special">,</span>
    <span class="keyword">typename</span> <span class="identifier">Traits</span><span class="special">,</span>
    <span class="keyword">typename</span> <span class="identifier">Allocator</span><span class="special">&gt;</span>
<span class="identifier">const_buffers_1</span> <a class="link" href="buffer/overload27.html" title="buffer (27 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span><span class="special">&lt;</span> <span class="identifier">Elem</span><span class="special">,</span> <span class="identifier">Traits</span><span class="special">,</span> <span class="identifier">Allocator</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload27.html" title="buffer (27 of 28 overloads)">more...</a></em></span>

<span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <span class="identifier">Elem</span><span class="special">,</span>
    <span class="keyword">typename</span> <span class="identifier">Traits</span><span class="special">,</span>
    <span class="keyword">typename</span> <span class="identifier">Allocator</span><span class="special">&gt;</span>
<span class="identifier">const_buffers_1</span> <a class="link" href="buffer/overload28.html" title="buffer (28 of 28 overloads)">buffer</a><span class="special">(</span>
    <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span><span class="special">&lt;</span> <span class="identifier">Elem</span><span class="special">,</span> <span class="identifier">Traits</span><span class="special">,</span> <span class="identifier">Allocator</span> <span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">data</span><span class="special">,</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_size_in_bytes</span><span class="special">);</span>
  <span class="emphasis"><em>&#187; <a class="link" href="buffer/overload28.html" title="buffer (28 of 28 overloads)">more...</a></em></span>
</pre>
<p>
        A buffer object represents a contiguous region of memory as a 2-tuple consisting
        of a pointer and size in bytes. A tuple of the form <code class="computeroutput"><span class="special">{</span><span class="keyword">void</span><span class="special">*,</span> <span class="identifier">size_t</span><span class="special">}</span></code> specifies a mutable (modifiable) region
        of memory. Similarly, a tuple of the form <code class="computeroutput"><span class="special">{</span><span class="keyword">const</span> <span class="keyword">void</span><span class="special">*,</span> <span class="identifier">size_t</span><span class="special">}</span></code> specifies a const (non-modifiable) region
        of memory. These two forms correspond to the classes <a class="link" href="mutable_buffer.html" title="mutable_buffer"><code class="computeroutput"><span class="identifier">mutable_buffer</span></code></a> and <a class="link" href="const_buffer.html" title="const_buffer"><code class="computeroutput"><span class="identifier">const_buffer</span></code></a>, respectively. To mirror
        C++'s conversion rules, a <a class="link" href="mutable_buffer.html" title="mutable_buffer"><code class="computeroutput"><span class="identifier">mutable_buffer</span></code></a> is implicitly convertible
        to a <a class="link" href="const_buffer.html" title="const_buffer"><code class="computeroutput"><span class="identifier">const_buffer</span></code></a>,
        and the opposite conversion is not permitted.
      </p>
<p>
        The simplest use case involves reading or writing a single buffer of a specified
        size:
      </p>
<pre class="programlisting"><span class="identifier">sock</span><span class="special">.</span><span class="identifier">send</span><span class="special">(</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">data</span><span class="special">,</span> <span class="identifier">size</span><span class="special">));</span>
</pre>
<p>
        In the above example, the return value of <code class="computeroutput"><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span></code>
        meets the requirements of the ConstBufferSequence concept so that it may
        be directly passed to the socket's write function. A buffer created for modifiable
        memory also meets the requirements of the MutableBufferSequence concept.
      </p>
<p>
        An individual buffer may be created from a builtin array, std::vector, std::array
        or boost::array of POD elements. This helps prevent buffer overruns by automatically
        determining the size of the buffer:
      </p>
<pre class="programlisting"><span class="keyword">char</span> <span class="identifier">d1</span><span class="special">[</span><span class="number">128</span><span class="special">];</span>
<span class="identifier">size_t</span> <span class="identifier">bytes_transferred</span> <span class="special">=</span> <span class="identifier">sock</span><span class="special">.</span><span class="identifier">receive</span><span class="special">(</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">d1</span><span class="special">));</span>

<span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span><span class="keyword">char</span><span class="special">&gt;</span> <span class="identifier">d2</span><span class="special">(</span><span class="number">128</span><span class="special">);</span>
<span class="identifier">bytes_transferred</span> <span class="special">=</span> <span class="identifier">sock</span><span class="special">.</span><span class="identifier">receive</span><span class="special">(</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">d2</span><span class="special">));</span>

<span class="identifier">std</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span><span class="keyword">char</span><span class="special">,</span> <span class="number">128</span><span class="special">&gt;</span> <span class="identifier">d3</span><span class="special">;</span>
<span class="identifier">bytes_transferred</span> <span class="special">=</span> <span class="identifier">sock</span><span class="special">.</span><span class="identifier">receive</span><span class="special">(</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">d3</span><span class="special">));</span>

<span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span><span class="keyword">char</span><span class="special">,</span> <span class="number">128</span><span class="special">&gt;</span> <span class="identifier">d4</span><span class="special">;</span>
<span class="identifier">bytes_transferred</span> <span class="special">=</span> <span class="identifier">sock</span><span class="special">.</span><span class="identifier">receive</span><span class="special">(</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">d4</span><span class="special">));</span>
</pre>
<p>
        In all three cases above, the buffers created are exactly 128 bytes long.
        Note that a vector is <span class="emphasis"><em>never</em></span> automatically resized when
        creating or using a buffer. The buffer size is determined using the vector's
        <code class="computeroutput"><span class="identifier">size</span><span class="special">()</span></code>
        member function, and not its capacity.
      </p>
<h5>
<a name="asio.reference.buffer.h0"></a>
        <span><a name="asio.reference.buffer.accessing_buffer_contents"></a></span><a class="link" href="buffer.html#asio.reference.buffer.accessing_buffer_contents">Accessing
        Buffer Contents</a>
      </h5>
<p>
        The contents of a buffer may be accessed using the <a class="link" href="buffer_size.html" title="buffer_size"><code class="computeroutput"><span class="identifier">buffer_size</span></code></a> and <a class="link" href="buffer_cast.html" title="buffer_cast"><code class="computeroutput"><span class="identifier">buffer_cast</span></code></a> functions:
      </p>
<pre class="programlisting"><span class="identifier">asio</span><span class="special">::</span><span class="identifier">mutable_buffer</span> <span class="identifier">b1</span> <span class="special">=</span> <span class="special">...;</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">s1</span> <span class="special">=</span> <span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">b1</span><span class="special">);</span>
<span class="keyword">unsigned</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">p1</span> <span class="special">=</span> <span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer_cast</span><span class="special">&lt;</span><span class="keyword">unsigned</span> <span class="keyword">char</span><span class="special">*&gt;(</span><span class="identifier">b1</span><span class="special">);</span>

<span class="identifier">asio</span><span class="special">::</span><span class="identifier">const_buffer</span> <span class="identifier">b2</span> <span class="special">=</span> <span class="special">...;</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">s2</span> <span class="special">=</span> <span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">b2</span><span class="special">);</span>
<span class="keyword">const</span> <span class="keyword">void</span><span class="special">*</span> <span class="identifier">p2</span> <span class="special">=</span> <span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer_cast</span><span class="special">&lt;</span><span class="keyword">const</span> <span class="keyword">void</span><span class="special">*&gt;(</span><span class="identifier">b2</span><span class="special">);</span>
</pre>
<p>
        The <code class="computeroutput"><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer_cast</span></code> function permits violations
        of type safety, so uses of it in application code should be carefully considered.
      </p>
<p>
        For convenience, the <a class="link" href="buffer_size.html" title="buffer_size"><code class="computeroutput"><span class="identifier">buffer_size</span></code></a> function also works
        on buffer sequences (that is, types meeting the ConstBufferSequence or MutableBufferSequence
        type requirements). In this case, the function returns the total size of
        all buffers in the sequence.
      </p>
<h5>
<a name="asio.reference.buffer.h1"></a>
        <span><a name="asio.reference.buffer.buffer_copying"></a></span><a class="link" href="buffer.html#asio.reference.buffer.buffer_copying">Buffer
        Copying</a>
      </h5>
<p>
        The <a class="link" href="buffer_copy.html" title="buffer_copy"><code class="computeroutput"><span class="identifier">buffer_copy</span></code></a>
        function may be used to copy raw bytes between individual buffers and buffer
        sequences.
      </p>
<p>
        In particular, when used with the <a class="link" href="buffer_size.html" title="buffer_size"><code class="computeroutput"><span class="identifier">buffer_size</span></code></a> , the <a class="link" href="buffer_copy.html" title="buffer_copy"><code class="computeroutput"><span class="identifier">buffer_copy</span></code></a> function can be used
        to linearise a sequence of buffers. For example:
      </p>
<pre class="programlisting"><span class="identifier">vector</span><span class="special">&lt;</span><span class="identifier">const_buffer</span><span class="special">&gt;</span> <span class="identifier">buffers</span> <span class="special">=</span> <span class="special">...;</span>

<span class="identifier">vector</span><span class="special">&lt;</span><span class="keyword">unsigned</span> <span class="keyword">char</span><span class="special">&gt;</span> <span class="identifier">data</span><span class="special">(</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">buffers</span><span class="special">));</span>
<span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer_copy</span><span class="special">(</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">data</span><span class="special">),</span> <span class="identifier">buffers</span><span class="special">);</span>
</pre>
<p>
        Note that <a class="link" href="buffer_copy.html" title="buffer_copy"><code class="computeroutput"><span class="identifier">buffer_copy</span></code></a>
        is implemented in terms of <code class="computeroutput"><span class="identifier">memcpy</span></code>,
        and consequently it cannot be used to copy between overlapping memory regions.
      </p>
<h5>
<a name="asio.reference.buffer.h2"></a>
        <span><a name="asio.reference.buffer.buffer_invalidation"></a></span><a class="link" href="buffer.html#asio.reference.buffer.buffer_invalidation">Buffer
        Invalidation</a>
      </h5>
<p>
        A buffer object does not have any ownership of the memory it refers to. It
        is the responsibility of the application to ensure the memory region remains
        valid until it is no longer required for an I/O operation. When the memory
        is no longer available, the buffer is said to have been invalidated.
      </p>
<p>
        For the <code class="computeroutput"><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span></code> overloads that accept an argument
        of type std::vector, the buffer objects returned are invalidated by any vector
        operation that also invalidates all references, pointers and iterators referring
        to the elements in the sequence (C++ Std, 23.2.4)
      </p>
<p>
        For the <code class="computeroutput"><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span></code> overloads that accept an argument
        of type std::basic_string, the buffer objects returned are invalidated according
        to the rules defined for invalidation of references, pointers and iterators
        referring to elements of the sequence (C++ Std, 21.3).
      </p>
<h5>
<a name="asio.reference.buffer.h3"></a>
        <span><a name="asio.reference.buffer.buffer_arithmetic"></a></span><a class="link" href="buffer.html#asio.reference.buffer.buffer_arithmetic">Buffer
        Arithmetic</a>
      </h5>
<p>
        Buffer objects may be manipulated using simple arithmetic in a safe way which
        helps prevent buffer overruns. Consider an array initialised as follows:
      </p>
<pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span><span class="keyword">char</span><span class="special">,</span> <span class="number">6</span><span class="special">&gt;</span> <span class="identifier">a</span> <span class="special">=</span> <span class="special">{</span> <span class="char">'a'</span><span class="special">,</span> <span class="char">'b'</span><span class="special">,</span> <span class="char">'c'</span><span class="special">,</span> <span class="char">'d'</span><span class="special">,</span> <span class="char">'e'</span> <span class="special">};</span>
</pre>
<p>
        A buffer object <code class="computeroutput"><span class="identifier">b1</span></code> created
        using:
      </p>
<pre class="programlisting"><span class="identifier">b1</span> <span class="special">=</span> <span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span>
</pre>
<p>
        represents the entire array, <code class="computeroutput"><span class="special">{</span> <span class="char">'a'</span><span class="special">,</span> <span class="char">'b'</span><span class="special">,</span> <span class="char">'c'</span><span class="special">,</span>
        <span class="char">'d'</span><span class="special">,</span> <span class="char">'e'</span> <span class="special">}</span></code>. An optional
        second argument to the <code class="computeroutput"><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span></code>
        function may be used to limit the size, in bytes, of the buffer:
      </p>
<pre class="programlisting"><span class="identifier">b2</span> <span class="special">=</span> <span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">a</span><span class="special">,</span> <span class="number">3</span><span class="special">);</span>
</pre>
<p>
        such that <code class="computeroutput"><span class="identifier">b2</span></code> represents the
        data <code class="computeroutput"><span class="special">{</span> <span class="char">'a'</span><span class="special">,</span> <span class="char">'b'</span><span class="special">,</span>
        <span class="char">'c'</span> <span class="special">}</span></code>.
        Even if the size argument exceeds the actual size of the array, the size
        of the buffer object created will be limited to the array size.
      </p>
<p>
        An offset may be applied to an existing buffer to create a new one:
      </p>
<pre class="programlisting"><span class="identifier">b3</span> <span class="special">=</span> <span class="identifier">b1</span> <span class="special">+</span> <span class="number">2</span><span class="special">;</span>
</pre>
<p>
        where <code class="computeroutput"><span class="identifier">b3</span></code> will set to represent
        <code class="computeroutput"><span class="special">{</span> <span class="char">'c'</span><span class="special">,</span> <span class="char">'d'</span><span class="special">,</span>
        <span class="char">'e'</span> <span class="special">}</span></code>.
        If the offset exceeds the size of the existing buffer, the newly created
        buffer will be empty.
      </p>
<p>
        Both an offset and size may be specified to create a buffer that corresponds
        to a specific range of bytes within an existing buffer:
      </p>
<pre class="programlisting"><span class="identifier">b4</span> <span class="special">=</span> <span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">b1</span> <span class="special">+</span> <span class="number">1</span><span class="special">,</span> <span class="number">3</span><span class="special">);</span>
</pre>
<p>
        so that <code class="computeroutput"><span class="identifier">b4</span></code> will refer to
        the bytes <code class="computeroutput"><span class="special">{</span> <span class="char">'b'</span><span class="special">,</span> <span class="char">'c'</span><span class="special">,</span>
        <span class="char">'d'</span> <span class="special">}</span></code>.
      </p>
<h5>
<a name="asio.reference.buffer.h4"></a>
        <span><a name="asio.reference.buffer.buffers_and_scatter_gather_i_o"></a></span><a class="link" href="buffer.html#asio.reference.buffer.buffers_and_scatter_gather_i_o">Buffers and
        Scatter-Gather I/O</a>
      </h5>
<p>
        To read or write using multiple buffers (i.e. scatter-gather I/O), multiple
        buffer objects may be assigned into a container that supports the MutableBufferSequence
        (for read) or ConstBufferSequence (for write) concepts:
      </p>
<pre class="programlisting"><span class="keyword">char</span> <span class="identifier">d1</span><span class="special">[</span><span class="number">128</span><span class="special">];</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span><span class="keyword">char</span><span class="special">&gt;</span> <span class="identifier">d2</span><span class="special">(</span><span class="number">128</span><span class="special">);</span>
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span><span class="keyword">char</span><span class="special">,</span> <span class="number">128</span><span class="special">&gt;</span> <span class="identifier">d3</span><span class="special">;</span>

<span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span><span class="identifier">mutable_buffer</span><span class="special">,</span> <span class="number">3</span><span class="special">&gt;</span> <span class="identifier">bufs1</span> <span class="special">=</span> <span class="special">{</span>
  <span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">d1</span><span class="special">),</span>
  <span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">d2</span><span class="special">),</span>
  <span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">d3</span><span class="special">)</span> <span class="special">};</span>
<span class="identifier">bytes_transferred</span> <span class="special">=</span> <span class="identifier">sock</span><span class="special">.</span><span class="identifier">receive</span><span class="special">(</span><span class="identifier">bufs1</span><span class="special">);</span>

<span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span><span class="identifier">const_buffer</span><span class="special">&gt;</span> <span class="identifier">bufs2</span><span class="special">;</span>
<span class="identifier">bufs2</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">d1</span><span class="special">));</span>
<span class="identifier">bufs2</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">d2</span><span class="special">));</span>
<span class="identifier">bufs2</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">d3</span><span class="special">));</span>
<span class="identifier">bytes_transferred</span> <span class="special">=</span> <span class="identifier">sock</span><span class="special">.</span><span class="identifier">send</span><span class="special">(</span><span class="identifier">bufs2</span><span class="special">);</span>
</pre>
<h5>
<a name="asio.reference.buffer.h5"></a>
        <span><a name="asio.reference.buffer.requirements"></a></span><a class="link" href="buffer.html#asio.reference.buffer.requirements">Requirements</a>
      </h5>
<p>
        <span class="emphasis"><em>Header: </em></span><code class="literal">asio/buffer.hpp</code>
      </p>
<p>
        <span class="emphasis"><em>Convenience header: </em></span><code class="literal">asio.hpp</code>
      </p>
</div>
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<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2014 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>
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