Because then you _have_ to have a variable to call the function - except
for the bizarre situation that struct literals have where they're
considered
lvalues (very bad idea IMHO). I think that from the perspective of most
programmers, the fact that const ref doesn't take rvalues is a major
negative,
even if Andrei is ultimately right (though I don't even remember what his
reasoning is - I'm not sure that I've ever understod it).
I guess it's what I said earlier, temporaries don't necessarily have an
address, e.g. being in a register.
