Re: [Boost-Users] Re: Mutex scoped_lock compile errors

From: Darren Vincent Hart (dvhart_at_[hidden])
Date: 2003-06-10 09:04:16

That did the trick, many thanks.  So why is it that the error talked
about argument types when it *should* have reported me attempting to
change a member variable within a const context ? (I admit to feeling a
bit abashed at the problem however :-) )

Thanks for the time,

Darren Hart
dvhart_at_[hidden]

On Tue, 2003-06-10 at 01:43, Russell Hind wrote:
> > logger.cpp:36: error: no matching function for call to `
> >    boost::detail::thread::scoped_lock<boost::mutex>::scoped_lock(const
> >    boost::mutex&)'
> 
> If the mutex is a member variable, then in the const method, it is a 
> const mutex.  scoped_lock requires a non-const mutex.  This is what is 
> causing the error.
> 
> Declare the mutex as mutable so it appears as non-const even in const 
> members.  (I don't know if this is the preferred way, but it is the way 
> I currently use).
> 
> It works if the mutex is declared in the .cpp because it is not part of 
> the class, and therefore isn't const when accessed inside a const method.
> 
> HTH
> 
> Russell
> 
> 
> 
> 
> 
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