<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Issue 874: Missing initializer_list constructor for discrete_distribution</title>
<meta property="og:title" content="Issue 874: Missing initializer_list constructor for discrete_distribution">
<meta property="og:description" content="C++ library issue. Status: Resolved">
<meta property="og:url" content="https://cplusplus.github.io/LWG/issue874.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#Resolved">Resolved</a> status.</em></p>
<h3 id="874"><a href="lwg-defects.html#874">874</a>. Missing <code>initializer_list</code> constructor for <code>discrete_distribution</code></h3>
<p><b>Section:</b> 29.5.9.6.1 <a href="https://wg21.link/rand.dist.samp.discrete">[rand.dist.samp.discrete]</a> <b>Status:</b> <a href="lwg-active.html#Resolved">Resolved</a>
 <b>Submitter:</b> Daniel Kr&uuml;gler <b>Opened:</b> 2008-08-22 <b>Last modified:</b> 2016-01-28</p>
<p><b>Priority: </b>Not Prioritized
</p>
<p><b>View all other</b> <a href="lwg-index.html#rand.dist.samp.discrete">issues</a> in [rand.dist.samp.discrete].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#Resolved">Resolved</a> status.</p>
<p><b>Discussion:</b></p>
<p>
During the Sophia Antipolis meeting it was decided to separate from <a href="lwg-defects.html#793" title="discrete_distribution missing constructor (Status: Resolved)">793</a><sup><a href="https://cplusplus.github.io/LWG/issue793" title="Latest snapshot">(i)</a></sup> a
subrequest that adds initializer list support to <code>discrete_distribution</code>, specifically,
the issue proposed to add a c'tor taking a <code>initializer_list&lt;double&gt;</code>.
</p>



<p id="res-874"><b>Proposed resolution:</b></p>
<ol>
<li>
<p>
In 29.5.9.6.1 <a href="https://wg21.link/rand.dist.samp.discrete">[rand.dist.samp.discrete]</a> p. 1, class <code>discrete_distribution</code>,
just <em>before</em> the member declaration
</p>

<blockquote><pre>
explicit discrete_distribution(const param_type&amp; parm);
</pre></blockquote>

<p>
insert
</p>

<blockquote><pre>
discrete_distribution(initializer_list&lt;double&gt; wl);
</pre></blockquote>
</li>

<li>
<p>
Between p.4 and p.5 of the same section insert a new
paragraph as part of the new member description:
</p>

<blockquote><pre>
discrete_distribution(initializer_list&lt;double&gt; wl);
</pre>

<blockquote><p>
<i>Effects:</i> Same as <code>discrete_distribution(wl.begin(), wl.end())</code>.
</p></blockquote>
</blockquote>
</li>
</ol>


<p><b>Rationale:</b></p><p>
Addressed by
<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2836.pdf">N2836</a> 
"Wording Tweaks for Concept-enabled Random Number Generation in C++0X".
</p>




</body>
</html>
