https://svn.boost.org/trac10/ticket/11193 <p> Self assignment of mpfr_float always results in a NaN: </p> <pre class="wiki"> boost::multiprecision::mpfr_float a = 2; a = a; // Sets a to a NaN </pre> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/11193 Trac 1.4.3 John Maddock Fri, 17 Apr 2015 07:48:17 GMT https://svn.boost.org/trac10/ticket/11193#comment:1 https://svn.boost.org/trac10/ticket/11193#comment:1 <ul> <li><strong>status</strong> <span class="trac-field-old">new</span> → <span class="trac-field-new">closed</span> </li> <li><strong>resolution</strong> → <span class="trac-field-new">fixed</span> </li> <li><strong>milestone</strong> <span class="trac-field-old">To Be Determined</span> → <span class="trac-field-new">Boost 1.59.0</span> </li> </ul> <p> Fixed in <a class="ext-link" href="https://github.com/boostorg/multiprecision/commit/c36e15bd292d3a6aa97091f4eec80e9f2f1b58d8"><span class="icon">​</span>https://github.com/boostorg/multiprecision/commit/c36e15bd292d3a6aa97091f4eec80e9f2f1b58d8</a> </p> Ticket