C++0x Concepts - Dead?

[Ary Borenszweig]

Walter Bright escribió:
> Jarrett Billingsley wrote:
>> Let's try to *simplify* metaprogramming and make things *orthogonal*
>> instead of tacking on features with no regard to the existing ones.
> 
> Type matching cannot do what expression matching can do. You'd need a 
> totally new syntax anyway to bring expression matching into the template 
> type parameter list.

But don't bring expression matching into the template type parameter 
list, bring template type parameter list into expression matching!

...

Done!

is(...)

"if" in the template is more powerful than template parameters 
restrictions. Why use those restrictions? Having two things for almost 
the same thing is confusing.

Suppose you implement partial ordering with template constraints and 
drop the others. What things you couldn't do? (I need an example because 
I can't see it).