erator1</span> last1<span class="special">,</span> 
                <span class="identifier">InputIterator2</span> first2<span class="special">,</span> <span class="identifier">InputIterator2</span> last2<span class="special">,</span> 
                <span class="identifier">command_queue</span> <span class="special">&amp;</span> queue <span class="special">=</span> <span class="identifier">system</span><span class="special">::</span><span class="identifier">default_queue</span><span class="special">(</spa