pan class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">octonion</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <a class="link" href="oct_non_mem.html#math_toolkit.oct_non_mem.binary_addition_operators">operator +</a> <span class="special">(::</span><span class="identifier">boost</span><span class="special">::