STL iterators and for loops

[Tor Lillqvist]

> My builds with --enable-dbgutil are noticeably slow,

Well, that is more or less the point, isn't it? That shows that 1) the
code is not compiled as optimised (and thus is easier to debug), and
2) it includes the extra debugging consistency checks etc.

> So, possibly we do not care.

I'd say that is the case, yes. As long as a dbgutil build is still
usable, it fills its purpose.

--tml

> OTOH, hoisting vec.end() so
> that is is called only once should be a quite mechanical task,

Mechanical tasks are typically those where it is very easy to miss
some crucial detail in some case and introduce a bug.

--tml