devdocs/c/language%2Ftypeof.html


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21

    <h1 id="firstHeading" class="firstHeading">typeof operators <span class="t-mark-rev t-since-c23">(since C23)</span>
</h1>            <p>Determines the type of an object.</p>
<h3 id="Syntax"> Syntax</h3> <table class="t-sdsc-begin">  <tr class="t-sdsc"> <td> <code>typeof(</code> <span class="t-spar">type</span> <code>)</code> </td> <td> (1) </td> <td class="t-sdsc-nopad"> </td>
</tr>  <tr class="t-sdsc"> <td> <code>typeof(</code> <span class="t-spar">expression</span> <code>)</code> </td> <td> (2) </td> <td class="t-sdsc-nopad"> </td>
</tr>  <tr class="t-sdsc"> <td> <code>typeof_unqual(</code> <span class="t-spar">type</span> <code>)</code> </td> <td> (3) </td> <td class="t-sdsc-nopad"> </td>
</tr>  <tr class="t-sdsc"> <td> <code>typeof_unqual(</code> <span class="t-spar">expression</span> <code>)</code> </td> <td> (4) </td> <td class="t-sdsc-nopad"> </td>
</tr> 
</table> <h3 id="Explanation"> Explanation</h3> <div class="t-li1">
<span class="t-li">1)</span> produces the type-name with any nested typeof-specifier evaluated </div> <div class="t-li1">
<span class="t-li">2)</span> yields the type-name representing the type of its operand. No implicit conversions are applied to <span class="t-spar">expression</span>.</div> <div class="t-li1">
<span class="t-li">3,4)</span> the same as <span class="t-v">(1)</span> and <span class="t-v">(2)</span> respectively but remove qualifiers</div> <h3 id="Notes"> Notes</h3> <p><code>typeof</code> and <code>typeof_unqual</code> are collectively called the <i>typeof operators</i>. The <code>typeof</code> operators cannot be applied to bit-field members. If the type of the operand is a variably modified type, the operand is evaluated; otherwise, the operand is not evaluated. The result of the <code>typeof_unqual</code> operator is the non-atomic unqualified type that would result from the <code>typeof</code> operator. The <code>typeof</code> operator preserves all qualifiers.</p>
<h3 id="Example"> Example</h3>  <h3 id="References"> References</h3>  <ul>
<li> C23 standard (ISO/IEC 9899:2023): </li>
<ul><li> 6.7.2.5 The typeof specifiers (p: 115-118) </li></ul>
</ul>   <h3 id="See_also"> See also</h3> <table class="t-dsc-begin"> <tr class="t-dsc"> <td colspan="2"> <span><a href="https://en.cppreference.com/w/cpp/language/decltype" title="cpp/language/decltype">C++ documentation</a></span> for <code>decltype</code> </td>
</tr> </table>           <div class="_attribution">
  <p class="_attribution-p">
    &copy; cppreference.com<br>Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.<br>
    <a href="https://en.cppreference.com/w/c/language/typeof" class="_attribution-link">https://en.cppreference.com/w/c/language/typeof</a>
  </p>
</div>