<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Issue 110: istreambuf_iterator::equal not const</title>
<meta property="og:title" content="Issue 110: istreambuf_iterator::equal not const">
<meta property="og:description" content="C++ library issue. Status: TC1">
<meta property="og:url" content="https://cplusplus.github.io/LWG/issue110.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#TC1">TC1</a> status.</em></p>
<h3 id="110"><a href="lwg-defects.html#110">110</a>. istreambuf_iterator::equal not const</h3>
<p><b>Section:</b> 24.6.4 <a href="https://wg21.link/istreambuf.iterator">[istreambuf.iterator]</a>, 24.6.4.4 <a href="https://wg21.link/istreambuf.iterator.ops">[istreambuf.iterator.ops]</a> <b>Status:</b> <a href="lwg-active.html#TC1">TC1</a>
 <b>Submitter:</b> Nathan Myers <b>Opened:</b> 1998-10-15 <b>Last modified:</b> 2023-02-07</p>
<p><b>Priority: </b>Not Prioritized
</p>
<p><b>View other</b> <a href="lwg-index-open.html#istreambuf.iterator">active issues</a> in [istreambuf.iterator].</p>
<p><b>View all other</b> <a href="lwg-index.html#istreambuf.iterator">issues</a> in [istreambuf.iterator].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#TC1">TC1</a> status.</p>
<p><b>Discussion:</b></p>
<p>Member istreambuf_iterator&lt;&gt;::equal is not declared
&quot;const&quot;, yet  [istreambuf.iterator::op==] says that operator==,
which is const, calls it. This is contradictory. </p>


<p id="res-110"><b>Proposed resolution:</b></p>
<p>In 24.6.4 <a href="https://wg21.link/istreambuf.iterator">[istreambuf.iterator]</a> and also in  [istreambuf.iterator::equal],
replace:</p>

<blockquote>
  <pre>bool equal(istreambuf_iterator&amp; b);</pre>
</blockquote>

<p>with:</p>

<blockquote>
  <pre>bool equal(const istreambuf_iterator&amp; b) const;</pre>
</blockquote>





</body>
</html>
