ConvertibleToConstBuffer.html 15 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218
  1. <html>
  2. <head>
  3. <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
  4. <title>Convertible to const buffer requirements</title>
  5. <link rel="stylesheet" href="../../boostbook.css" type="text/css">
  6. <meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
  7. <link rel="home" href="../../index.html" title="Asio">
  8. <link rel="up" href="../reference.html" title="Reference">
  9. <link rel="prev" href="ConstBufferSequence.html" title="Constant buffer sequence requirements">
  10. <link rel="next" href="ConvertibleToMutableBuffer.html" title="Convertible to mutable buffer requirements">
  11. </head>
  12. <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
  13. <table cellpadding="2" width="100%"><tr><td valign="top"><img alt="asio C++ library" width="250" height="60" src="../../asio.png"></td></tr></table>
  14. <hr>
  15. <div class="spirit-nav">
  16. <a accesskey="p" href="ConstBufferSequence.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="ConvertibleToMutableBuffer.html"><img src="../../next.png" alt="Next"></a>
  17. </div>
  18. <div class="section">
  19. <div class="titlepage"><div><div><h3 class="title">
  20. <a name="asio.reference.ConvertibleToConstBuffer"></a><a class="link" href="ConvertibleToConstBuffer.html" title="Convertible to const buffer requirements">Convertible
  21. to const buffer requirements</a>
  22. </h3></div></div></div>
  23. <p>
  24. A type that meets the requirements for convertibility to a const buffer must
  25. meet the requirements of <code class="computeroutput"><span class="identifier">CopyConstructible</span></code>
  26. types (C++ Std, 20.1.3), and the requirements of <code class="computeroutput"><span class="identifier">Assignable</span></code>
  27. types (C++ Std, 23.1).
  28. </p>
  29. <p>
  30. In the table below, <code class="computeroutput"><span class="identifier">X</span></code> denotes
  31. a class meeting the requirements for convertibility to a const buffer, <code class="computeroutput"><span class="identifier">a</span></code> and <code class="computeroutput"><span class="identifier">b</span></code>
  32. denote values of type <code class="computeroutput"><span class="identifier">X</span></code>,
  33. and <code class="computeroutput"><span class="identifier">u</span></code>, <code class="computeroutput"><span class="identifier">v</span></code>
  34. and <code class="computeroutput"><span class="identifier">w</span></code> denote identifiers.
  35. </p>
  36. <div class="table">
  37. <a name="asio.reference.ConvertibleToConstBuffer.t0"></a><p class="title"><b>Table&#160;6.&#160;ConvertibleToConstBuffer requirements</b></p>
  38. <div class="table-contents"><table class="table" summary="ConvertibleToConstBuffer requirements">
  39. <colgroup>
  40. <col>
  41. <col>
  42. </colgroup>
  43. <thead><tr>
  44. <th>
  45. <p>
  46. expression
  47. </p>
  48. </th>
  49. <th>
  50. <p>
  51. postcondition
  52. </p>
  53. </th>
  54. </tr></thead>
  55. <tbody>
  56. <tr>
  57. <td>
  58. <p>
  59. </p>
  60. <pre class="programlisting"><span class="identifier">const_buffer</span> <span class="identifier">u</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span>
  61. <span class="identifier">const_buffer</span> <span class="identifier">v</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span>
  62. </pre>
  63. <p>
  64. </p>
  65. </td>
  66. <td>
  67. <p>
  68. </p>
  69. <pre class="programlisting"><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">u</span><span class="special">)</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">v</span><span class="special">)</span>
  70. <span class="special">&amp;&amp;</span> <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">buffer_size</span><span class="special">(</span><span class="identifier">v</span><span class="special">)</span>
  71. </pre>
  72. <p>
  73. </p>
  74. </td>
  75. </tr>
  76. <tr>
  77. <td>
  78. <p>
  79. </p>
  80. <pre class="programlisting"><span class="identifier">const_buffer</span> <span class="identifier">u</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span>
  81. <span class="identifier">const_buffer</span> <span class="identifier">v</span> <span class="special">=</span> <span class="identifier">a</span><span class="special">;</span>
  82. </pre>
  83. <p>
  84. </p>
  85. </td>
  86. <td>
  87. <p>
  88. </p>
  89. <pre class="programlisting"><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">u</span><span class="special">)</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">v</span><span class="special">)</span>
  90. <span class="special">&amp;&amp;</span> <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">buffer_size</span><span class="special">(</span><span class="identifier">v</span><span class="special">)</span>
  91. </pre>
  92. <p>
  93. </p>
  94. </td>
  95. </tr>
  96. <tr>
  97. <td>
  98. <p>
  99. </p>
  100. <pre class="programlisting"><span class="identifier">const_buffer</span> <span class="identifier">u</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span>
  101. <span class="identifier">const_buffer</span> <span class="identifier">v</span><span class="special">;</span> <span class="identifier">v</span> <span class="special">=</span> <span class="identifier">a</span><span class="special">;</span>
  102. </pre>
  103. <p>
  104. </p>
  105. </td>
  106. <td>
  107. <p>
  108. </p>
  109. <pre class="programlisting"><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">u</span><span class="special">)</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">v</span><span class="special">)</span>
  110. <span class="special">&amp;&amp;</span> <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">buffer_size</span><span class="special">(</span><span class="identifier">v</span><span class="special">)</span>
  111. </pre>
  112. <p>
  113. </p>
  114. </td>
  115. </tr>
  116. <tr>
  117. <td>
  118. <p>
  119. </p>
  120. <pre class="programlisting"><span class="identifier">const_buffer</span> <span class="identifier">u</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span>
  121. <span class="keyword">const</span> <span class="identifier">X</span><span class="special">&amp;</span> <span class="identifier">v</span> <span class="special">=</span> <span class="identifier">a</span><span class="special">;</span>
  122. <span class="identifier">const_buffer</span> <span class="identifier">w</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span>
  123. </pre>
  124. <p>
  125. </p>
  126. </td>
  127. <td>
  128. <p>
  129. </p>
  130. <pre class="programlisting"><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">u</span><span class="special">)</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">w</span><span class="special">)</span>
  131. <span class="special">&amp;&amp;</span> <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">buffer_size</span><span class="special">(</span><span class="identifier">w</span><span class="special">)</span>
  132. </pre>
  133. <p>
  134. </p>
  135. </td>
  136. </tr>
  137. <tr>
  138. <td>
  139. <p>
  140. </p>
  141. <pre class="programlisting"><span class="identifier">const_buffer</span> <span class="identifier">u</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span>
  142. <span class="identifier">X</span> <span class="identifier">v</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span>
  143. <span class="identifier">const_buffer</span> <span class="identifier">w</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span>
  144. </pre>
  145. <p>
  146. </p>
  147. </td>
  148. <td>
  149. <p>
  150. </p>
  151. <pre class="programlisting"><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">u</span><span class="special">)</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">w</span><span class="special">)</span>
  152. <span class="special">&amp;&amp;</span> <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">buffer_size</span><span class="special">(</span><span class="identifier">w</span><span class="special">)</span>
  153. </pre>
  154. <p>
  155. </p>
  156. </td>
  157. </tr>
  158. <tr>
  159. <td>
  160. <p>
  161. </p>
  162. <pre class="programlisting"><span class="identifier">const_buffer</span> <span class="identifier">u</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span>
  163. <span class="identifier">X</span> <span class="identifier">v</span> <span class="special">=</span> <span class="identifier">a</span><span class="special">;</span>
  164. <span class="identifier">const_buffer</span> <span class="identifier">w</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span>
  165. </pre>
  166. <p>
  167. </p>
  168. </td>
  169. <td>
  170. <p>
  171. </p>
  172. <pre class="programlisting"><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">u</span><span class="special">)</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">w</span><span class="special">)</span>
  173. <span class="special">&amp;&amp;</span> <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">buffer_size</span><span class="special">(</span><span class="identifier">w</span><span class="special">)</span>
  174. </pre>
  175. <p>
  176. </p>
  177. </td>
  178. </tr>
  179. <tr>
  180. <td>
  181. <p>
  182. </p>
  183. <pre class="programlisting"><span class="identifier">const_buffer</span> <span class="identifier">u</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span>
  184. <span class="identifier">X</span> <span class="identifier">v</span><span class="special">(</span><span class="identifier">b</span><span class="special">);</span> <span class="identifier">v</span> <span class="special">=</span> <span class="identifier">a</span><span class="special">;</span>
  185. <span class="identifier">const_buffer</span> <span class="identifier">w</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span>
  186. </pre>
  187. <p>
  188. </p>
  189. </td>
  190. <td>
  191. <p>
  192. </p>
  193. <pre class="programlisting"><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">u</span><span class="special">)</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">w</span><span class="special">)</span>
  194. <span class="special">&amp;&amp;</span> <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">buffer_size</span><span class="special">(</span><span class="identifier">w</span><span class="special">)</span>
  195. </pre>
  196. <p>
  197. </p>
  198. </td>
  199. </tr>
  200. </tbody>
  201. </table></div>
  202. </div>
  203. <br class="table-break">
  204. </div>
  205. <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
  206. <td align="left"></td>
  207. <td align="right"><div class="copyright-footer">Copyright &#169; 2003-2014 Christopher M. Kohlhoff<p>
  208. Distributed under the Boost Software License, Version 1.0. (See accompanying
  209. 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>)
  210. </p>
  211. </div></td>
  212. </tr></table>
  213. <hr>
  214. <div class="spirit-nav">
  215. <a accesskey="p" href="ConstBufferSequence.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="ConvertibleToMutableBuffer.html"><img src="../../next.png" alt="Next"></a>
  216. </div>
  217. </body>
  218. </html>