[MPI3 Fortran] Results of San Jose Forum meeting

[Aleksandar Donev]

Hi,

You guys have been busy but unfortunately I do not see much progress, 
sorry.

On Thursday 11 March 2010, Bill Long wrote:
> type,bind(c) :: MPI_Comm
>      integer(c_int) :: val
> end type MPI_Comm
If indeed someone insists on specifying the internals, use:

INTEGER(MPI_COMM) :: handle

What on earth is wrong with that?

Striving for type-safety and striving to:
> One advantage of the integer flag values is that it avoids interface
> issues when we change the pointer size.
are at odds with one another. It is like saying a typealias provides 
type safety. It does not, only *subtyping* does, which Fortran does not 
have. A derived type with one integer component is, in Fortran, and 
almost in C, soo different from an integer that it is not worth trying 
to pretend they are the same thing. Sticking SEQUENCE will do nothing 
for a type of only one single component, either in practice or in 
theory. BIND(C), as Bill proposes, is infinitely better, if someone 
insists on a derived type (for type safety or whatever reasons).

Best,
Aleks

-- 
Aleksandar Donev, Ph.D.
Luis W. Alvarez Postdoctoral Fellow
Center for Computational Sciences and Engineering (https://ccse.lbl.gov)
Lawrence Berkeley National Laboratory (http://www.lbl.gov)
E-mail: adonev at lbl.gov
Phone: (510) 486-5782  Fax: (510) 486-6900
Address: MS 50A-1148, LBL, 1 Cyclotron Rd., Berkeley, CA 94720
Web: http://cims.nyu.edu/~donev/