From: John Maddock (john_at_[hidden])
Date: 2004-11-29 11:04:29
> 1) a corrected version of is_abstract_template_test.cpp
I've updated is_abstract test with your tests, found that VC7.1 has the same
bug (?) as gcc-3.4 BTW.
> 2) a patch to boost/type_traits/is_abstract.hpp that works around gcc
> bug #17232.
> I would not be surprised if my patch turns out to be overly
> complicated. I had assumed that any expression that involves
> sizeof(T) causes the instantiation of T if T is a template
> specialization. So I tried, e.g., to add the condition
> sizeof(T) > 0 to the parameter list of ice_and in is_abstract_imp.
> For some reason, though, whatever I tried showed no effect.
> (Perhaps the compiler realized that the conditions I added were
> true for any type T and eliminated the evaluation of sizeof(T)?)
> I finally settled for attached patch that adds a further struct in
> which SFINAE is used again.
I've simplified your fix down to a:
which also does the trick quite nicely.
I'm running all the type traits tests through now, as long as there are no
unexpected hiccups it'll all be in cvs soon.
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