Re: [boost] Submission: typelist

From: Andrei Alexandrescu (andrewalex_at_[hidden])
Date: 2001-11-26 11:26:55

From: "Geurt Vos" <G.Vos_at_[hidden]>
> > Unless you need to pass _instances_ of typelists around, of
> > course. Is there such a need?
> >
>
> For testing I sometimes have code like:
>
> std::ostream &operator <<(std::ostream &os, NullType)
> {
>     return os;
> }
>
> template <typename Head, class Tail>
> std::ostream &operator <<(std::ostream &os, TypeList<Head,Tail>)
> {
>     os << typeid(Head).name() << ' ' << Tail();
>     return os;
> }

Exactly. Typelists need to be instantiable because that is of help in
passing them around to overloaded functions.

Andrei