Re: [boost] [type_traits] is_convertible<noncopyable,To> crashes

From: John Maddock (john_at_[hidden])
Date: 2006-04-15 13:26:55

> [On a side note, if From must be different to To, why is
> this is not stated in the docs? There's even a case
> whith From=To in is_convertible_test.cpp:
>
>   BOOST_CHECK_INTEGRAL_CONSTANT(
>     (::tt::is_convertible<Base,Base>::value), true);
>
> end of side note.]

Um, because I overstated the case :-)  They can be the same, it just doesn't 
tell you anything useful: either the result is true (T is 
copy-constructible) or the code doesn't compile.

> So, if we exclude the case where From=To, is is_convertible
> supposed to work for the call pattern
>
>   is_convertible<const X,Y>
>
> where X is non-copyable and Y!=X? From Alexei tests seems like
> this could be failing too, and does not fall under the
> forbidden From=To case. I don't have any compiler handy right
> now, will try to check out by myself in a few days.

No that should work just fine, indeed that was the test case attached to my 
last message.

John.