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  26 <div class="titlepage"><div><div><h4 class="title">
  27 <a name="beast.ref.boost__beast__websocket__seed_prng"></a><a class="link" href="boost__beast__websocket__seed_prng.html" title="websocket::seed_prng">websocket::seed_prng</a>
  28 </h4></div></div></div>
  29 <p>
  30         <a class="indexterm" name="idm45873474316160"></a>
  31 Manually provide a one-time seed to initialize the PRNG.
  32       </p>
  33 <h5>
  34 <a name="beast.ref.boost__beast__websocket__seed_prng.h0"></a>
  35         <span class="phrase"><a name="beast.ref.boost__beast__websocket__seed_prng.synopsis"></a></span><a class="link" href="boost__beast__websocket__seed_prng.html#beast.ref.boost__beast__websocket__seed_prng.synopsis">Synopsis</a>
  36       </h5>
  37 <p>
  38         Defined in header <code class="literal">&lt;<a href="../../../../../../boost/beast/websocket/stream.hpp" target="_top">boost/beast/websocket/stream.hpp</a>&gt;</code>
  39       </p>
  40 <pre class="programlisting"><span class="keyword">void</span>
  41 <span class="identifier">seed_prng</span><span class="special">(</span>
  42     <span class="identifier">std</span><span class="special">::</span><span class="identifier">seed_seq</span><span class="special">&amp;</span> <span class="identifier">ss</span><span class="special">);</span>
  43 </pre>
  44 <h5>
  45 <a name="beast.ref.boost__beast__websocket__seed_prng.h1"></a>
  46         <span class="phrase"><a name="beast.ref.boost__beast__websocket__seed_prng.description"></a></span><a class="link" href="boost__beast__websocket__seed_prng.html#beast.ref.boost__beast__websocket__seed_prng.description">Description</a>
  47       </h5>
  48 <p>
  49         This function invokes the specified seed sequence to produce a seed suitable
  50         for use with the pseudo-random number generator used to create masks and
  51         perform WebSocket protocol handshakes. If a seed is not manually provided,
  52         the implementation will perform a one-time seed generation using <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">random_device</span></code>.
  53         This function may be used when the application runs in an environment where
  54         the random device is unreliable or does not provide sufficient entropy.
  55       </p>
  56 <h5>
  57 <a name="beast.ref.boost__beast__websocket__seed_prng.h2"></a>
  58         <span class="phrase"><a name="beast.ref.boost__beast__websocket__seed_prng.preconditions"></a></span><a class="link" href="boost__beast__websocket__seed_prng.html#beast.ref.boost__beast__websocket__seed_prng.preconditions">Preconditions</a>
  59       </h5>
  60 <p>
  61         This function may not be called after any websocket <a class="link" href="boost__beast__websocket__stream.html" title="websocket::stream"><code class="computeroutput"><span class="identifier">websocket</span><span class="special">::</span><span class="identifier">stream</span></code></a> objects have been constructed.
  62       </p>
  63 <h5>
  64 <a name="beast.ref.boost__beast__websocket__seed_prng.h3"></a>
  65         <span class="phrase"><a name="beast.ref.boost__beast__websocket__seed_prng.parameters"></a></span><a class="link" href="boost__beast__websocket__seed_prng.html#beast.ref.boost__beast__websocket__seed_prng.parameters">Parameters</a>
  66       </h5>
  67 <div class="informaltable"><table class="table">
  68 <colgroup>
  69 <col>
  70 <col>
  71 </colgroup>
  72 <thead><tr>
  73 <th>
  74                 <p>
  75                   Name
  76                 </p>
  77               </th>
  78 <th>
  79                 <p>
  80                   Description
  81                 </p>
  82               </th>
  83 </tr></thead>
  84 <tbody><tr>
  85 <td>
  86                 <p>
  87                   <code class="computeroutput"><span class="identifier">ss</span></code>
  88                 </p>
  89               </td>
  90 <td>
  91                 <p>
  92                   A reference to a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">seed_seq</span></code>
  93                   which will be used to seed the pseudo-random number generator.
  94                   The seed sequence should have at least 256 bits of entropy.
  95                 </p>
  96               </td>
  97 </tr></tbody>
  98 </table></div>
  99 <h5>
 100 <a name="beast.ref.boost__beast__websocket__seed_prng.h4"></a>
 101         <span class="phrase"><a name="beast.ref.boost__beast__websocket__seed_prng.see_also"></a></span><a class="link" href="boost__beast__websocket__seed_prng.html#beast.ref.boost__beast__websocket__seed_prng.see_also">See Also</a>
 102       </h5>
 103 <p>
 104         <a class="link" href="boost__beast__websocket__stream/secure_prng.html" title="websocket::stream::secure_prng"><code class="computeroutput"><span class="identifier">websocket</span><span class="special">::</span><span class="identifier">stream</span><span class="special">::</span><span class="identifier">secure_prng</span></code></a>
 105       </p>
 106 <p>
 107         Convenience header <code class="literal">&lt;<a href="../../../../../../boost/beast/websocket.hpp" target="_top">boost/beast/websocket.hpp</a>&gt;</code>
 108       </p>
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