<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Issue 551: &lt;ccomplex&gt;</title>
<meta property="og:title" content="Issue 551: &lt;ccomplex&gt;">
<meta property="og:description" content="C++ library issue. Status: CD1">
<meta property="og:url" content="https://cplusplus.github.io/LWG/issue551.html">
<meta property="og:type" content="website">
<meta property="og:image" content="http://cplusplus.github.io/LWG/images/cpp_logo.png">
<meta property="og:image:alt" content="C++ logo">
<style>
  p {text-align:justify}
  li {text-align:justify}
  pre code.backtick::before { content: "`" }
  pre code.backtick::after { content: "`" }
  blockquote.note
  {
    background-color:#E0E0E0;
    padding-left: 15px;
    padding-right: 15px;
    padding-top: 1px;
    padding-bottom: 1px;
  }
  ins {background-color:#A0FFA0}
  del {background-color:#FFA0A0}
  table.issues-index { border: 1px solid; border-collapse: collapse; }
  table.issues-index th { text-align: center; padding: 4px; border: 1px solid; }
  table.issues-index td { padding: 4px; border: 1px solid; }
  table.issues-index td:nth-child(1) { text-align: right; }
  table.issues-index td:nth-child(2) { text-align: left; }
  table.issues-index td:nth-child(3) { text-align: left; }
  table.issues-index td:nth-child(4) { text-align: left; }
  table.issues-index td:nth-child(5) { text-align: center; }
  table.issues-index td:nth-child(6) { text-align: center; }
  table.issues-index td:nth-child(7) { text-align: left; }
  table.issues-index td:nth-child(5) span.no-pr { color: red; }
  @media (prefers-color-scheme: dark) {
     html {
        color: #ddd;
        background-color: black;
     }
     ins {
        background-color: #225522
     }
     del {
        background-color: #662222
     }
     a {
        color: #6af
     }
     a:visited {
        color: #6af
     }
     blockquote.note
     {
        background-color: rgba(255, 255, 255, .10)
     }
  }
</style>
</head>
<body>
<hr>
<p><em>This page is a snapshot from the LWG issues list, see the <a href="lwg-active.html">Library Active Issues List</a> for more information and the meaning of <a href="lwg-active.html#CD1">CD1</a> status.</em></p>
<h3 id="551"><a href="lwg-defects.html#551">551</a>. &lt;ccomplex&gt;</h3>
<p><b>Section:</b> 17.15 <a href="https://wg21.link/support.c.headers">[support.c.headers]</a> <b>Status:</b> <a href="lwg-active.html#CD1">CD1</a>
 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2006-01-23 <b>Last modified:</b> 2023-02-07</p>
<p><b>Priority: </b>Not Prioritized
</p>
<p><b>View all other</b> <a href="lwg-index.html#support.c.headers">issues</a> in [support.c.headers].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#CD1">CD1</a> status.</p>
<p><b>Discussion:</b></p>
<p>
Previously xxx.h was parsable by C++.  But in the case of C99's &lt;complex.h&gt;
it isn't.  Otherwise we could model it just like &lt;string.h&gt;, &lt;cstring&gt;, &lt;string&gt;:
</p>

<ul>
<li>&lt;string&gt;   : C++ API in namespace std</li>
<li>&lt;cstring&gt;  : C API in namespace std</li>
<li>&lt;string.h&gt; : C API in global namespace</li>
</ul>

<p>
In the case of C's complex, the C API won't compile in C++.  So we have:
</p>

<ul>
<li>&lt;complex&gt;   : C++ API in namespace std</li>
<li>&lt;ccomplex&gt;  : ?</li>
<li>&lt;complex.h&gt; : ?</li>
</ul>

<p>
The ? can't refer to the C API.  TR1 currently says:
</p>

<ul>
<li>&lt;complex&gt;   : C++ API in namespace std</li>
<li>&lt;ccomplex&gt;  : C++ API in namespace std</li>
<li>&lt;complex.h&gt; : C++ API in global namespace</li>
</ul>



<p id="res-551"><b>Proposed resolution:</b></p>
<p>
Change 26.3.11 [cmplxh]:
</p>

<blockquote>
<p>
The header behaves as if it includes the header
<code>&lt;ccomplex&gt;</code><ins>.</ins><del>, and provides sufficient using
declarations to declare in the global namespace all function and type names
declared or defined in the neader <code>&lt;complex&gt;</code>.</del>
<ins>[<i>Note:</i> <code>&lt;complex.h&gt;</code> does not promote any interface
into the global namespace as there is no C interface to promote. <i>--end
note</i>]</ins>
</p>
</blockquote>






</body>
</html>
