https://svn.boost.org/trac10/ticket/12429 <p> 1 biot (cgs unit of current) is converted to 0.1 Ampere. It should be 10 Ampere. </p> <pre class="wiki">#include &lt;boost/units/systems/cgs/io.hpp&gt; #include &lt;boost/units/systems/si/io.hpp&gt; #include &lt;iostream&gt; using std::cout; int main(){ using namespace boost::units; cout &lt;&lt; 1.*cgs::biot &lt;&lt; " = " &lt;&lt; quantity&lt;si::current&gt;(1.*cgs::biot) &lt;&lt; '\n'; // not ok! "1 Bi = 0.1 A" cout &lt;&lt; 1.*cgs::centimeter &lt;&lt; " = " &lt;&lt; quantity&lt;si::length&gt;(1.*cgs::centimeter) &lt;&lt; '\n'; cout &lt;&lt; 1.*cgs::gram &lt;&lt; " = " &lt;&lt; quantity&lt;si::mass&gt;(1.*cgs::gram) &lt;&lt; '\n'; } </pre><p> The solution is change -1 by 1 in "boost/units/base_units/cgs/biot.hpp" </p> <p> from </p> <pre class="wiki">typedef scaled_base_unit&lt;boost::units::si::ampere_base_unit, scale&lt;10, static_rational&lt;-1&gt; &gt; &gt; </pre><p> to </p> <pre class="wiki">typedef scaled_base_unit&lt;boost::units::si::ampere_base_unit, scale&lt;10, static_rational&lt;1&gt; &gt; &gt; </pre> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/12429 Trac 1.4.3 Jürgen Hunold Fri, 11 Nov 2016 17:50:52 GMT https://svn.boost.org/trac10/ticket/12429#comment:1 https://svn.boost.org/trac10/ticket/12429#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> </ul> <p> Merged PR <a class="ext-link" href="https://github.com/boostorg/units/pull/23"><span class="icon">​</span>https://github.com/boostorg/units/pull/23</a> to develop and to master this week </p> Ticket