(j3.2006) kind conversion for intent(in), value dummy arguments

[Lionel, Steve]

> > In C's calling-by-value convention, there is an implicit conversion
> on
> > the caller site to match the explicit interface.  So even the user
> > uses a different kind value (say int vs long long int), the compiler
> > makes sure on the caller site, the conversion happens.  This is a
> > quite useful feature in C that lacks in Fortran's VALUE attribute.
> We
> > may consider to add this to Fortran C-interop TR.
> 
> If we do this at all, it should be a general feature of the VALUE
> attribute, not some wart stuck on C interop.  It ought to be defined
in
> terms of assignment, probably including defined assignment.

Intel Fortran, as an extension, does implicit KIND conversions for
constant actual arguments in the presence of an explicit, non-generic
interface. It does not do type conversions (integer to real, etc.). I
don't think we considered doing this for any kind of VALUE argument, but
I agree it seems worthwhile.  I agree with Van that it should be a
general property of VALUE.  I would NOT like to see this in terms of
assignment, defined or intrinsic, but rather in terms of implicit type
conversion as is defined for expressions.  (Again, I think this should
be for kind differences only.)

I'm less comfortable with how this would play with generic resolution.

Steve Lionel
Developer Products Division
Intel Corporation
Nashua, NH