Andy Little <andy <at> servocomm.freeserve.co.uk> writes:
I wonder if the three functions are necessary together?
Either there should only be promote or there should only be integral_promotion, float_promotion.
I was never sure about floating_point_promotion<> and promote<>. Section 13.3.3.1.1 of the standard conviced me to add them. It defines Promotion category of standard conversion sequences.
The main rationale for integral_promotion is for enums. float promotion and promotion usage are already handled by Boost.Typeof.
I would say, floating_point_promotion<> is easily implementable even without Boost.Typeof.
ints and floats are very different entities and I wonder if its approporiate to apply the same behaviours.
I agree.
I dont really like the fact types unrelated to int or floats can silently pass through as a general rule, but I think I see the reasoning given the use cases. It could be documented though.
It's documented by not emphasized: type: T if integral promotion can't be applied to an rvalue of type T; otherwise, a type of integral promotion of an rvalue of type T. Resulting type is same cv-qualified as T.
I think it needs some more rationale and examples. I understand its meant to fit with type_traits, but the documentation for other type_traits does include examples and there is room for a bit of rationale too.
Only few type_traits classes are explained in tutorial. I can't add mine without asking the authors.
I vote yes to accept it.
Thanks. -- Alexander Nasonov