Re: [boost] BOOST_ASSERT and __assume on MSVC

From: Rob Stewart (stewart_at_[hidden])
Date: 2005-09-19 12:42:10

From: "Marcin Kalicinski" <kalita_at_[hidden]>
> 
> I think we should rather base on NDEBUG macro, the same that determines the 
> behavior of assert. The whole change then boils down to adding these 6 lines 
> at the end of assert.hpp:
> 
> #include <boost/config.hpp>
> #if defined(BOOST_MSVC) && defined(NDEBUG)
> # define BOOST_ASSUME(e) { BOOST_ASSERT(e); if (e); else __assume(0); }

Interesting.  I'd have thought that calling __assume(0) was
useless, but it tells the optimizer that the else clause won't
occur.  I wonder if that will work at all or as well as
BOOST_ASSERT(e); __assume(e);.

There's a real problem with your solution, however: you evaluate
the expression twice.  Won't the simpler, more direct form work?

-- 
Rob Stewart                           stewart_at_[hidden]
Software Engineer                     http://www.sig.com
Susquehanna International Group, LLP  using std::disclaimer;