In practice it's much easier to use assignment or copy construction, thus avoiding the dangerous memcpy. Same goes for those memsets and bzero's beloved of C-programmers: just make the class do it for you; it always works, cannot be forgotten, cannot be done wrong, and is just much easier to begin with.
Or, if you have a C-struct you need to interface with, just declare it as 'foo myfoo = {0};'. That also zero's out the whole thing, and the compiler won't get the size wrong.
