[boost] Re: typeof for vintage compilers

From: Arkadiy Vertleyb (vertleyb_at_[hidden])
Date: 2004-08-20 17:44:41

"Peder Holt" <peder.holt_at_[hidden]> wrote

> I have implemented typeof for
> compilers not supporting partial specialization.

Before taking a closer look at your code, I assume that the only way to
emulate partial template specialization is by employing template function
overloading (I've done it once in the past)...  If this is what you did, I
wonder if base-derived classes are handled correctly...

> The max depth of an expression increased
> from the mpl limit of 60
> to the preprocessor limit of 256

Is this a real limit in MPL?  I've always gotten 50, but I assumed it should
be easy to lift...  Seems unreasonably low...

Can MPL experts comment on this?

> template expressions containing integral values are allowed
>
> The template:
> template<typename T,unsigned long V>
> struct X {};
> can be exposed to typeof in the following way:
> BOOST_TYPEOF_DEFINE_TEMPLATE(X,2,(typename,unsigned long))

This is cool, I will definitely try to implement something similar.

> (VC 7.1 had some problems preprocessing the code needed to make this
work.)

This will have to be solved, though, I believe this compiler deserves not to
be overlooked :)

Regards,

Arkadiy