Re: [boost] BOOST_ASSUME review needed?

From: Thorsten Ottosen (nesotto_at_[hidden])
Date: 2005-09-21 08:58:17

Marcin Kalicinski <kalita <at> poczta.onet.pl> writes:

> 
> >> What is the next step so that we can move forward towards adding
> >> BOOST_ASSUME
> >> macro to assert.hpp header?
> >
> > Why is this not just the release configuration of BOOST_ASSERT?
> 
> That was the original idea but it was noted that it may break existing code 
> (see excerpt below). 
> 
> As I read the documentation, currently code like:
> 
>     if (!p) {
>         BOOST_ASSERT( false );
>         return;
>     }
> 
> is supported and meaningful. If BOOST_DISABLE_ASSERTS is true, the macro
> does nothing and the return statement is executed when p is 0. If we
> change the macro to instead expand to __assume, then the compiler will
> probably omit both return and the check against zero. The documented
> behaviour of the code will change.

I don't get it. If you put BOOST_ASSERT( false ) anywhere, then you
effectively say "never exceute this code". Otherwise there is an error
in the assertion itself.

So I don't see how it can break anything.

(The effect of removing an assertion must not be any in a correct program).

-Thorsten