Re: Is there a way in Fortran to designate an integer value as integer*8 ?

On 10/24/2024 1:28 AM, Thomas Koenig wrote:

Lynn McGuire <lynnmcguire5@gmail.com> schrieb:
 

I am going to change all the F77 code to C++ some day.  I already have a
heavily modified version of F2C that I have rewritten extensively and
already moved several hundred subroutines from F77 to C++.

 Modern Fortran might be the easier way, because a change can be done
incrementally, and this...
 

The biggest
problem is the F77 write statements.

 ... would not be an issue.  What features is modern Fortran missing that
you need C++ for?
 

F2C fixes the other big problem
automatically, the change of initial array index from one to zero.

 If I remember correctly, it does so by issueing invalid C (or
C++), by using negative offsets from pointers.  Might work now,
might not work tomorrow.
 But note the IIRC above.

I want to move to a monolanguage environment.  50,000 lines of my calculation engine are C++ already.  850,000 lines to go.
Here is a portion of the translated C++ code from a subroutine called vapres.f.  component_data1.triplepointtemperature is a previous fortran common block variable, it is now a static.  The index before was [k], now it is [k - 1].  t and star are an argument variables.
int vapres (integer k, doublereal t, doublereal *ps, char *star, doublereal *apc,
doublereal *atb, doublereal *atc, longint *idcomp, doublereal *zcd)
{
     if (t <= component_data1.triplepointtemperature[k - 1]) {
solid_vapor_pressure (k, t, ps);
*star = ' ';
goto L99999;
     }
L99999:
     if (*ps < 1e-20) {
*ps = 1e-20;
     }
     if (*ps > 1e6) {
*ps = 1e6;
     }
     return 0;
} /* vapres */
Lynn