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<title>Issue 506: Requirements of Distribution parameter for variate_generator</title>
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<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">NAD</a> status.</em></p>
<h3 id="506"><a href="lwg-closed.html#506">506</a>. Requirements of Distribution parameter for variate_generator</h3>
<p><b>Section:</b> 29.5 <a href="https://wg21.link/rand">[rand]</a>, 99 [tr.rand.var] <b>Status:</b> <a href="lwg-active.html#NAD">NAD</a>
 <b>Submitter:</b> Walter Brown <b>Opened:</b> 2005-07-03 <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">issues</a> in [rand].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#NAD">NAD</a> status.</p>
<p><b>Discussion:</b></p>
<p>
Paragraph 3 requires that template argument U (which corresponds to template
parameter Engine) satisfy all uniform random number generator requirements.
However, there is no  analogous requirement regarding the template argument
that corresponds to template parameter Distribution.  We believe there should
be, and that it should require that this template argument satisfy all random
distribution requirements.
</p>


<p id="res-506"><b>Proposed resolution:</b></p>
<p>
Consequence 1: Remove the precondition clauses [tr.rand.var]/16 and /18.
</p>
<p>
Consequence 2: Add max() and min() functions to those distributions that
do not already have them.
</p>

<p><i>[
Mont Tremblant: Jens reccommends NAD, min/max not needed everywhere.
Marc supports having min and max to satisfy generic programming interface.
]</i></p>




<p><b>Rationale:</b></p>
<p>Berlin:  N1932 makes this moot: variate_generator has been eliminated.</p>





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