Re: [Boost-users] 1.45: thread/condition_variable.hpp: unused variable 'res' warning, gcc 4.2

Subject: Re: [Boost-users] 1.45: thread/condition_variable.hpp: unused variable 'res' warning, gcc 4.2
From: Anthony Williams (anthony.ajw_at_[hidden])
Date: 2011-01-06 08:28:04

"Hicham Mouline" <hicham_at_[hidden]> writes:

> in Release build in Xcode, gcc 4.2.1, 
>
> inline void condition_variable::wait(unique_lock<mutex>& m)
> {
> ...
>  int const res = pthread_cond_wait(&cond, &internal_mutex);
>  BOOST_ASSERT(!res);
>  ...
> }
>
> Unused variable 'res'
>
> is gcc mistaken?

Yes and no :-)

In the release build the assert compiles to nothing, so res is no longer
referenced, even though it is referenced in the source.

Anthony
-- 
Author of C++ Concurrency in Action     http://www.stdthread.co.uk/book/
just::thread C++0x thread library             http://www.stdthread.co.uk
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