f="mem_typedef.html" title="Quaternion Member Typedefs">value_type</a><span class="special">;</span>

   <span class="keyword">explicit</span> <a class="link" href="quat_mem_fun.html#math_toolkit.quat_mem_fun.constructors">quaternion</a><span class="special">(</span><span class="identifier">T</span> <span class="keyword">const</span> <span class="special">&amp;</span> <span class="identifier">requested_a</span> <span class="special">=</span> <span class="identifier">T</span><span class="special">(),</span> 