 given an argument of type ArgT?&quot;.</p>
<p>
Like 2, and unlike 1, function pointers or plain C++ functors, is_odd is a true lazy, polymorphic functor (rank-2 polymorphic functoid, in <a href="http://www.cc.gatech.edu/~yannis/fc++/">
FC++</a> jargon). The Phoenix functor version is fully polymorphic and works with any container (of ints, of doubles, of complex, etc.) as long as its elements can handle the &quot;arg1 % 2 == 1&quot; expression. However, unlike 2, this is more efficient and has less overhea