<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Issue 3026: filesystem::weakly_canonical still defined in terms of canonical(p, base)</title>
<meta property="og:title" content="Issue 3026: filesystem::weakly_canonical still defined in terms of canonical(p, base)">
<meta property="og:description" content="C++ library issue. Status: C++20">
<meta property="og:url" content="https://cplusplus.github.io/LWG/issue3026.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#C++20">C++20</a> status.</em></p>
<h3 id="3026"><a href="lwg-defects.html#3026">3026</a>. <code>filesystem::weakly_canonical</code> still defined in terms of <code>canonical(p, base)</code></h3>
<p><b>Section:</b> 31.12.13.40 <a href="https://wg21.link/fs.op.weakly.canonical">[fs.op.weakly.canonical]</a> <b>Status:</b> <a href="lwg-active.html#C++20">C++20</a>
 <b>Submitter:</b> Jonathan Wakely <b>Opened:</b> 2017-10-14 <b>Last modified:</b> 2021-06-06</p>
<p><b>Priority: </b>0
</p>
<p><b>View all other</b> <a href="lwg-index.html#fs.op.weakly.canonical">issues</a> in [fs.op.weakly.canonical].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#C++20">C++20</a> status.</p>
<p><b>Discussion:</b></p>
<p>
LWG <a href="lwg-defects.html#2956" title="filesystem::canonical() still defined in terms of absolute(p, base) (Status: C++17)">2956</a><sup><a href="https://cplusplus.github.io/LWG/issue2956" title="Latest snapshot">(i)</a></sup> fixed <code>canonical</code> to no longer use a base path, but <code>weakly_canonical</code> should have been
changed too:
</p>
<blockquote><p>
<i>Effects:</i> Using <code>status(p)</code> or <code>status(p, ec)</code>, respectively, to determine
existence, return a path composed by <code>operator/=</code> from the result of calling <code>canonical()</code> without
a <code>base</code> argument and with a [&hellip;]
</p></blockquote>
<p>
Since <code>canonical</code> doesn't accept a <code>base</code> argument, it doesn't make sense
to talk about calling it without one.
</p>

<p><i>[
2017-10-16 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
]</i></p>

<p><i>[2018-3-17 Adopted in Jacksonville]</i></p>



<p id="res-3026"><b>Proposed resolution:</b></p>
<p>This wording is relative to <a href="https://wg21.link/n4687">N4687</a>.</p>

<ol>
<li><p>Change  [fs.op.weakly_canonical] as indicated:</p>

<blockquote>
<pre>
path weakly_canonical(const path&amp; p);
path weakly_canonical(const path&amp; p, error_code&amp; ec);
</pre>
<blockquote>
<p>
-1- <i>Returns:</i> [&hellip;]
<p/>
-2- <i>Effects:</i> Using <code>status(p)</code> or <code>status(p, ec)</code>, respectively, to determine existence, return a path
composed by <code>operator/=</code> from the result of calling <code>canonical()</code> <del>without a <code>base</code> argument and</del>
with a path argument composed of the leading elements of <code>p</code> that exist, if any, followed by the elements of <code>p</code>
that do not exist, if any. For the first form, <code>canonical()</code> is called without an <code>error_code</code> argument.
For the second form, <code>canonical()</code> is called with ec as an <code>error_code</code> argument, and <code>path()</code> is returned
at the first error occurrence, if any.
<p/>
[&hellip;]
</p>
</blockquote>
</blockquote>
</li>
</ol>





</body>
</html>
