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| <div class="section" id="sizeof"> |
| <h1><a class="toc-backref" href="./miscellaneous.html#id1571">sizeof_</a></h1> |
| <div class="section" id="id1207"> |
| <h3><a class="subsection-title" href="#synopsis" name="synopsis">Synopsis</a></h3> |
| <pre class="literal-block"> |
| template< |
| typename X |
| > |
| struct <a href="./sizeof.html" class="identifier">sizeof_</a> |
| { |
| typedef <em>unspecified</em> type; |
| }; |
| </pre> |
| </div> |
| <div class="section" id="id1208"> |
| <h3><a class="subsection-title" href="#description" name="description">Description</a></h3> |
| <p>Returns the result of a <tt class="literal"><span class="pre">sizeof(X)</span></tt> expression wrapped into an |
| <a class="reference internal" href="./integral-constant.html">Integral Constant</a> of the corresponding type, <tt class="literal"><span class="pre">std::<a href="./size-t.html" class="identifier">size_t</a></span></tt>.</p> |
| </div> |
| <div class="section" id="id1209"> |
| <h3><a class="subsection-title" href="#header" name="header">Header</a></h3> |
| <pre class="literal-block"> |
| #include <<a href="../../../../boost/mpl/sizeof.hpp" class="header">boost/mpl/sizeof.hpp</a>> |
| </pre> |
| </div> |
| <div class="section" id="id1210"> |
| <h3><a class="subsection-title" href="#model-of" name="model-of">Model of</a></h3> |
| <p><a class="reference internal" href="./metafunction.html">Metafunction</a></p> |
| </div> |
| <div class="section" id="id1211"> |
| <h3><a class="subsection-title" href="#parameters" name="parameters">Parameters</a></h3> |
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| <col width="25%" /> |
| <col width="56%" /> |
| </colgroup> |
| <thead valign="bottom"> |
| <tr><th class="head">Parameter</th> |
| <th class="head">Requirement</th> |
| <th class="head">Description</th> |
| </tr> |
| </thead> |
| <tbody valign="top"> |
| <tr><td><tt class="literal"><span class="pre">X</span></tt></td> |
| <td>Any type</td> |
| <td>A type to compute the <tt class="literal"><span class="pre">sizeof</span></tt> for.</td> |
| </tr> |
| </tbody> |
| </table> |
| </div> |
| <div class="section" id="id1212"> |
| <h3><a class="subsection-title" href="#expression-semantics" name="expression-semantics">Expression semantics</a></h3> |
| <p>For an arbitrary type <tt class="literal"><span class="pre">x</span></tt>:</p> |
| <pre class="literal-block"> |
| typedef <a href="./sizeof.html" class="identifier">sizeof_</a><x>::type n; |
| </pre> |
| <table class="docutils field-list" frame="void" rules="none"> |
| <col class="field-name" /> |
| <col class="field-body" /> |
| <tbody valign="top"> |
| <tr class="field"><th class="field-name">Return type:</th><td class="field-body"><p class="first"><a class="reference internal" href="./integral-constant.html">Integral Constant</a>.</p> |
| </td> |
| </tr> |
| <tr class="field"><th class="field-name">Precondition:</th><td class="field-body"><p class="first"><tt class="literal"><span class="pre">x</span></tt> is a complete type.</p> |
| </td> |
| </tr> |
| <tr class="field"><th class="field-name">Semantics:</th><td class="field-body"><p class="first">Equivalent to</p> |
| <pre class="last literal-block"> |
| typedef <a href="./size-t.html" class="identifier">size_t</a>< sizeof(x) > n; |
| </pre> |
| </td> |
| </tr> |
| </tbody> |
| </table> |
| </div> |
| <div class="section" id="id1213"> |
| <h3><a class="subsection-title" href="#complexity" name="complexity">Complexity</a></h3> |
| <p>Constant time.</p> |
| </div> |
| <div class="section" id="id1214"> |
| <h3><a class="subsection-title" href="#example" name="example">Example</a></h3> |
| <pre class="literal-block"> |
| struct udt { char a[100]; }; |
| |
| <a href="./assert-relation.html" class="identifier">BOOST_MPL_ASSERT_RELATION</a>( <a href="./sizeof.html" class="identifier">sizeof_</a><char>::value, ==, sizeof(char) ); |
| <a href="./assert-relation.html" class="identifier">BOOST_MPL_ASSERT_RELATION</a>( <a href="./sizeof.html" class="identifier">sizeof_</a><int>::value, ==, sizeof(int) ); |
| <a href="./assert-relation.html" class="identifier">BOOST_MPL_ASSERT_RELATION</a>( <a href="./sizeof.html" class="identifier">sizeof_</a><double>::value, ==, sizeof(double) ); |
| <a href="./assert-relation.html" class="identifier">BOOST_MPL_ASSERT_RELATION</a>( <a href="./sizeof.html" class="identifier">sizeof_</a><udt>::value, ==, sizeof(my) ); |
| </pre> |
| </div> |
| <div class="section" id="id1215"> |
| <h3><a class="subsection-title" href="#see-also" name="see-also">See also</a></h3> |
| <p><a class="reference internal" href="./metafunctions.html">Metafunctions</a>, <a class="reference internal" href="./integral-constant.html">Integral Constant</a>, <a class="reference internal" href="./size-t.html">size_t</a></p> |
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