<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Issue 2494: [fund.ts.v2] ostream_joiner needs noexcept</title>
<meta property="og:title" content="Issue 2494: [fund.ts.v2] ostream_joiner needs noexcept">
<meta property="og:description" content="C++ library issue. Status: TS">
<meta property="og:url" content="https://cplusplus.github.io/LWG/issue2494.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#TS">TS</a> status.</em></p>
<h3 id="2494"><a href="lwg-defects.html#2494">2494</a>. [fund.ts.v2] <code>ostream_joiner</code> needs <code>noexcept</code></h3>
<p><b>Section:</b> 10.2 <a href="https://cplusplus.github.io/fundamentals-ts/v2.html#iterator.ostream.joiner">[fund.ts.v2::iterator.ostream.joiner]</a> <b>Status:</b> <a href="lwg-active.html#TS">TS</a>
 <b>Submitter:</b> Nate Wilson <b>Opened:</b> 2015-05-03 <b>Last modified:</b> 2017-07-30</p>
<p><b>Priority: </b>0
</p>
<p><b>View all issues with</b> <a href="lwg-status.html#TS">TS</a> status.</p>
<p><b>Discussion:</b></p>
<p><b>Addresses: fund.ts.v2</b></p>
<p>
In Library Fundamentals 2 
<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4481.html#iterator.ostream.joiner.ops">N4481</a>, 
[iterator.ostream.joiner], all operations are no-ops other than the assignment operator.
<p/>
So, they should be marked as <code>noexcept</code>.
</p>

<p><i>[2015-05, Lenexa]</i></p>

<p>
Move to Immediate.
</p>


<p id="res-2494"><b>Proposed resolution:</b></p>
<p>This wording is relative to N4481 in regard to fundamental-ts-2 changes.</p>

<ol>
<li><p>Change class template <code>ostream_joiner</code> synopsis, [iterator.ostream.joiner] p2, as indicated:</p>

<blockquote>
<pre>
namespace std {
namespace experimental {
inline namespace fundamentals_v2 {

template &lt;class DelimT, class charT = char, class traits = char_traits&lt;charT&gt; &gt;
  class ostream_joiner {
  public:
    [&hellip;]
    ostream_joiner&lt;DelimT, charT,traits&gt;&amp; operator*() <ins>noexcept</ins>;
    ostream_joiner&lt;DelimT, charT,traits&gt;&amp; operator++() <ins>noexcept</ins>;
    ostream_joiner&lt;DelimT, charT,traits&gt;&amp; operator++(int) <ins>noexcept</ins>;
    [&hellip;]
  };

} // inline namespace fundamentals_v2
} // namespace experimental
} // namespace std
</pre>
</blockquote>
</li>

<li><p>Change [iterator.ostream.joiner.ops] p3+5, as indicated:</p>

<blockquote>
<pre>
ostream_joiner&lt;DelimT, charT, traits&gt;&amp; operator*() <ins>noexcept</ins>;
</pre>
<p>
[&hellip;]
</p>
<pre>
ostream_joiner&lt;DelimT, charT, traits&gt;&amp; operator++() <ins>noexcept</ins>;
ostream_joiner&lt;DelimT, charT, traits&gt;&amp; operator++(int) <ins>noexcept</ins>;
</pre>
</blockquote>

</li>
</ol>





</body>
</html>
