Re: [boost] Please look at my suggested pimpl library in the file vault.

From: Rob Stewart (stewart_at_[hidden])
Date: 2005-10-04 13:56:25

From: "Asger Mangaard" <tmb_at_[hidden]>
> > Rob Stewart wrote
> >
> > I just downloaded the library and it still does a shallow copy.
> > If you intend something else, then you need to rethink how you
> > handle copying.
> 
> Could you be more specific? I really don't see where it shallows it.

Oops.  I looked again.  You're calling get() and that returns a
reference.  I had std::auto_ptr<T>::get(), for example, in mind
when I saw that.  You're fine, although *this = rhs is unusual
for a copy constructor.

> > I think you should have a boost::pimpls namespace.  In that
> > you can have the pimpl class and the supplied policies.
> I renamed the policies namespace to pimpls. I keep the class itself inside
> the boost namespace to shorten the name, eg. boost:pimpl instead of
> boost::pimpls::pimpl.

If someone wants it shortened, they can use a using declaration.
I'm not sure this warrants being directly in the boost
namespace.

> > * I'm not sure whether manual_creation should be a separate
> >   policy.
> >
> > Why not have the default policy have a constructor taking a raw
> > pointer, defaulted to a null pointer, plus provide a set() member
> > function?  You'd need to implement set() just as it is in
> > manual_creation now.
> 
> But then you remove the default creation which is one of the advantages of
> the library.

Ummm, yeah.  Sorry.  I was only paying attention to one side of
that coin, it seems.

It occurs to me that the creation policy names could be shortened
to "lazy," "manual," and "default_."

> > * pimpl's member functions should be inlined.
> >
> > They are all trivial, so you should make them inline.
> Aren't templates always inlined?

Nope.  They work just like non-templated (member) functions.

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