On 10/3/05, Rob Stewart <stewart@sig.com> wrote:
(Note that __assume(false) is useless, for it is an expression that the optimizer cannot use to optimize anything. So, while I understand that you were trying to simplify things for the discussion, let's also not lose sight of what is really meant when writing __assume(false) in the above examples.)
I think you're wrong. __assume(false) means that this code will never be executed, and as such isnt useless for the optimizer. if(x) { // do something here } else { __assume(false); BOOST_LOG(dbg) << "Error! this code should never execute!" << std::endl; } tells the optimizer that the else will never be taken and that the compiler can elide this and do not write the LOG code. When you write __assume(x != 0) it means to the optimizer that he can assume that x will always be different from 0. When you write __assume(false) it means that that place can never be reached. -- Felipe Magno de Almeida Developer from synergy and Computer Science student from State University of Campinas(UNICAMP). Unicamp: http://www.ic.unicamp.br Synergy: http://www.synergy.com.br "There is no dark side of the moon really. Matter of fact it's all dark."