iso_fortran_env

[Janne Blomqvist]

Steve Kargl wrote:
> On Tue, Aug 29, 2006 at 08:52:44AM -0700, Vivek Rao wrote:
>> For Lahey/Fujitsu Fortran for Linux, the values of the
>> constants in the ISO_FORTRAN_ENV module are shown
>> below. I'd like to write an analogous module that I
>> can use in gfortran, until the module is implemented
>> in the compiler. What would the values be, for
>> gfortran on Windows -- i386-pc-mingw32? Thanks.
>>  
>> module ISO_FORTRAN_ENV
>>
>>   ! Nonintrinsic version for Lahey/Fujitsu Fortran for
>> Linux.
>>   ! See Subclause 13.8.2 of the Fortran 2003 standard.
>>
>>   implicit NONE
>>   public
>>
>>   integer, parameter :: Character_Storage_Size = 8
>>   integer, parameter :: Error_Unit = 0
>>   integer, parameter :: File_Storage_Size = 8
>>   integer, parameter :: Input_Unit = 5
>>   integer, parameter :: IOSTAT_END = -1
>>   integer, parameter :: IOSTAT_EOR = -2
>>   integer, parameter :: Numeric_Storage_Size = 32
>>   integer, parameter :: Output_Unit = 6
>>
>> end module ISO_FORTRAN_ENV 
> 
> Everthing above matches gfortran with the possible exception of
> File_Storage_Size and Numeric_Storage_Size.  I don't F2003
> handy.  What do these values means?

IIRC file storage size is the number of bits per storage element. E.g. 
when you do a inquire(iolength) you get the answer as an integer 
multiple of the file storage size. Analogously, numeric storage size is 
the size in bits of a scalar variable of default kind.

Or something like that, I'm too lazy to look into F2003 atm.



-- 
Janne Blomqvist