Re: [boost] [type traits] add a set of templates to propagate constetc from one type to another?

What about something like

qualify_from< From, To, Interest >

qualify_from<const int, int>::type would be 'const int'

qualify_from<volatile int, int>::type would be 'volatile int'

qualify_from<const volatile int, int, const void>::type would be 'const int'

qualify_from<const volatile int, int, volatile void>::type would be 'volatile int'

and I suppose ...

qualify_from<int, const int>::type could be 'int'