Re: [boost] Re: What I Hate About How We Abstract System Dependence

From: Rob Stewart (stewart_at_[hidden])
Date: 2005-03-07 21:31:28

From: Bob Bell <belvis_at_[hidden]>
> 
> Another possibility is to provide another level of indirection. For
> example, boost::thread can have an accessor which returns a
> boost::platform_thread, which has the OS thread ID, plus member functions
> which mimic OS operations not reflected in the portable (boost::thread) API.
> The advantage of this approach is that boost::platform_thread member
> functions may be able to preserve invariants that otherwise might be broken
> if the user was allowed to manipulate the underlying OS thread ID itself, and
> if the coverage of the boost::platform_thread member functions is large
> enough, it might not even be necessary to expose the OS thread ID at all.

That means that everything possible on a given OS should be
provided -- ultimately, anyway -- but at least it would be done
once, right, and safely.  I like it.

The concern is how that type is related to the portable type.  If
it is to maintain invariants, it has to know a great deal about
the portable type.  Perhaps it could contain a (reference to a)
special type derived from the portable type that provides access
to more implementation details/APIs that enable it to maintain
invariants while it offers an expanded interface.

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