"Gennadiy Rozental" <gennadiy.rozental@thomson.com> writes:
"Gennadiy Rozental" <gennadiy.rozental@thomson.com> writes:
Well, technically you maybe right, though it's quite difficult to imagine an example of that.
char_traits is one.
But If I understood you correctly in some other place you say that char_traits is an example of bad design.
Yes. That doesn't change the fact that it acts in both ways.
And I think the same. IMO any example of trait/policy mixure in the same class would be an example of bad design.
I don't know; it seems to me that the template <class T, class Policy = xxx_traits<T> > class Foo; idiom might not be a bad one for some uses if xxx_traits is only supplying associated types. It allows customization of the meaning of Foo<X> for any X by specializing xxx_traits<X>, while also allowing users to explicitly choose Foo<X, Y> when they don't like the default for X. -- Dave Abrahams Boost Consulting www.boost-consulting.com