RE: [Boost-Users] Boost.Threads question

From: William E. Kempf (wekempf_at_[hidden])
Date: 2002-12-04 13:48:04

James Zappia said:
> Thank you, that worked.  I see what I was doing wrong.
>
> One thing I don't understand about the alternative method...
>
>>   boost::try_mutex::scoped_try_lock lock(mutex);  // does a try_lock
>> while (!lock) {
>>      cout << "trying...";
>>      lock.try_lock();
>>   }
>
> How does "!lock" in the "while (!lock) { ... }" statement determine
> whether it's true or false?  Does it call a function in the
> scoped_try_lock class? (sorry if that's a lame question...)

Hmmm... this doesn't seem to be documented very well.  I'll have to fix
that.  What it does is invoke operator void*() for a boolean test (this
mechanism also should be updated to use the safe_bool idiom as well). 
Alternatively, you could call lock.locked() (which also appears to be
poorly documented).  Thanks for pointing out these deficiencies.

William E. Kempf