[MPI3 Fortran] Fwd: [Mpi-comments] MPI 3.0: Fortran 2008 interface - issue with the LOGICAL kind

[Malcolm Cohen]

Bill Long writes:
>The value of C_BOOL as a Fortran KIND type for LOGICAL is such that
>
>1) The bitsize of LOGICAL(C_BOOL) matches the bitsize of _Bool in C for the 
>companion processor.
>
>2) The Fortran processor uses the internal bit pattern in LOGICAL (C_BOOL) of 0 
>to represent false, and 1 to represent true.

Nick Maclaren asks:
>Does it?  I can't find that in the Fortran standard.  Either I have
>missed it, or this is a wart that we should consider for the next
>revision.

I think this is inherent in the meaning of the word "interoperable": if the 
internal representation is different, it cannot interoperate (though we fudged 
that with unsigned...).  This could be clarified editorially in the next 
revision.

Cheers,
-- 
................................Malcolm Cohen, Nihon NAG, Tokyo.