Alexander Nasonov writes:
Aleksey Gurtovoy wrote:
Oh, I see it now: specializing 'iter_apply1' allows for intuitively obvious
find_if< overloads, is_same<bool(int),_1> >
while my suggestion would require something like
find_if< overloads , overload_match< _1, is_same<bool(int),_1> > >
Exactly!
That's indeed quite appealing. However, specializing 'iter_apply1' this way assumes that it's always invoked on a predicate metafunction, which, at least theoretically, does not hold.
Either predicate or metafunction that returns IntegralConstant constructed from sizeof (possibly shifted).
On the other hand, with 'typeof', dereferencing 'overload_set_iter' would simply return a corresponding function type and things would "just work"
That's true.
... without any special effort on our side, and in that light 'iter_apply1' specialization for the compilers that need it is simply an implementation detail which I'm willing to close my eyes to ;). It's going to be interesting to see how many MPL algorithms can be made to work with overload sequences using this approach.
I've already tried find find_if contains and equal.
Here is my plan. For now, we can reimplement mpl algorithms based on predicate using iter_applyN. Later, when typeof becomes common among popular compilers we can switch seamlessly to typeof.
Sounds good. Looking forward to hearing how it goes! -- Aleksey Gurtovoy MetaCommunications Engineering