<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Issue 648: regex_iterator c'tor needs clarification/editorial fix</title>
<meta property="og:title" content="Issue 648: regex_iterator c'tor needs clarification/editorial fix">
<meta property="og:description" content="C++ library issue. Status: NAD Editorial">
<meta property="og:url" content="https://cplusplus.github.io/LWG/issue648.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#NAD_Editorial">NAD Editorial</a> status.</em></p>
<h3 id="648"><a href="lwg-closed.html#648">648</a>. regex_iterator c'tor needs clarification/editorial fix</h3>
<p><b>Section:</b> 28.6.11.1.2 <a href="https://wg21.link/re.regiter.cnstr">[re.regiter.cnstr]</a> <b>Status:</b> <a href="lwg-active.html#NAD_Editorial">NAD Editorial</a>
 <b>Submitter:</b> Daniel Kr&uuml;gler <b>Opened:</b> 2007-03-03 <b>Last modified:</b> 2016-01-28</p>
<p><b>Priority: </b>Not Prioritized
</p>
<p><b>View all issues with</b> <a href="lwg-status.html#NAD Editorial">NAD Editorial</a> status.</p>
<p><b>Discussion:</b></p>
<p>
In 28.6.11.1.2 <a href="https://wg21.link/re.regiter.cnstr">[re.regiter.cnstr]</a>/2 the effects paragraph starts with:
</p>

<blockquote>
<p>
<i>Effects:</i> Initializes begin and end to point to the beginning and the
end of the target sequence, sets pregex to &amp;re, sets flags to f,[..]
</p></blockquote>

<p>
There are two issues with this description:
</p>

<ol>
<li>
The meaning of very first part of this quote is unclear, because
there is no target sequence provided, instead there are given two
parameters a and b, both of type BidirectionalIterator. The mentioned
part does not explain what a and b represent.
</li>
<li>
There does not exist any parameter f, but instead a parameter
m in the constructor declaration, so this is actually an editorial
fix.
</li>
</ol>


<p id="res-648"><b>Proposed resolution:</b></p>
<p>
In 28.6.11.1.2 <a href="https://wg21.link/re.regiter.cnstr">[re.regiter.cnstr]</a>/2 change the above quoted part by
</p>

<blockquote><p>
<i>Effects:</i> Initializes <code>begin</code> and <code>end</code> to point to
the beginning and the end of the target sequence <ins>designated by the
iterator range <code>[a, b)</code></ins>, sets <code>pregex</code> to
<code>&amp;re</code>, sets <code>flags</code> to <code><del>f</del>
<ins>m</ins></code>, then calls <code>regex_search(begin, end, match,
*pregex, flags)</code>. If this call returns <code>false</code> the
constructor sets <code>*this</code> to the end-of-sequence iterator.
</p></blockquote>





</body>
</html>
