Ranges

[Lutger]

Steve Teale wrote:
...
> Robert Fraser Wrote:
>> As others have mentioned, it's just a struct (or other type) that
>> happens to support certain operations.
> 
> So does this mean that interfaces are just a tragic mistake. I'd always
> thought that what you said was a pretty good description of what an
> interface is!

Could you explain why that makes interfaces a mistake? Interfaces (as in 
classes implementing an interface) do provide dynamic polymorphism which 
these compile time constraints (or 'concepts' in STL terms) don't.