From: Aleksey Gurtovoy (agurtovoy_at_[hidden])
Date: 2002-04-02 15:13:58
Vesa Karvonen wrote:
> >I think we can make the placeholders work, though perhaps under a
> >different syntax that above, e.g.:
> >typedef variant<int, float, string, rec1<aggr, variant_self> > value;
> If I recall correctly, the above has the problem that it is
> not portable when used with standard containers, because
> a standard container template may have extra defaulted template
> parameters. This breaks the template template parameter match.
> > // rec2, rec3, etc. should be pretty obvious
> Hopefully there is a way to avoid using names that include
> the number of parameters. I don't know if an ideal solution exists
> within the current C++ core language. Member templates would
> probably mean more work for users.
MPL's lambda facility can allow us to do this:
typedef variant<int, float, string, aggr<_1> > value;
// or 'typedef variant<int, float, string, aggr<_> > value;'
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