(j3.2006) Requiring identity of polymorphic arguments' declared types is too strong

[Van Snyder]

On Fri, 2016-10-21 at 09:00 +0900, Cohen Malcolm wrote:
> >The requirement that allocatable or polymorphic dummy and actual
> >arguments have the same declared type is too strong.
> 
> No it is not.  Losing that would seriously damage type safety.

Is this an objection to losing compile-time checking, or is type safety
really lost?  If so, how?

> Cheers,