[MPI3 Fortran] MPI-2.1: Fortran 90 bindings

[Lionel, Steve]

Harald Klimach wrote:

> It would be very nice, if Fortran would allow the assumed 
> size notation in a generic interface to consume all ranks. 
> Which would mean that you'd have to use assumed shape 
> arrays if you want to explicitly use different routines 
> for different ranks and both options would be mutually 
> exclusive.

I discussed this with our Fortran standards rep last week. Intel and
many other vendors have extensions that allow for this, but we agreed
that the standard should be amended to allow for the option.  I
suggested that as part of the C interoperability that a "VOID" argument
attribute be added which would serve the same purpose it does in C.

Absent that, Fortran allows you to pass an element of an array of any
rank to an array argument of any rank, such as:

Call sub(a(1))

Fortran specifies that the remaining elements in the actual argument
array are "sequence associated" with the corresponding elements of the
dummy argument.

Fortran does NOT allow passing a scalar variable or expression to an
array dummy argument.

Steve Lionel
Intel