Thread: Extracting an integer + real array from a pointer location

I have a structure (void *cbdata) in memory created from Fortran. It contains:
2 integers, then (up to) 100 doubles

I need to extract the ints and doubles. I am doing this on the C side:

Code:

  int *nvar = (int *) cbData;
  double *vars = (double *)((int)cbData + 8);

but I get warnings:
ex_nlp3.c(33): warning C4311: 'type cast': pointer truncation from 'void *' to 'int'
ex_nlp3.c(33): warning C4312: 'type cast': conversion from 'int' to 'double *' of greater size

Both warnings relate to the double line of code.

How should I restructure this to eliminate the warnings?

Originally Posted by Salem

Are you sure that your Fortran buffer is aligned correctly for accessing ints and doubles?

Yes, as I created the Fortran structure as follows:

Code:

type t_box
  sequence
  integer              :: nvar, ncall
  real(8)              :: vars(100)
end type

I didn't like to do this, I would have preferred vars to be an allocatable array (sized at runtime to nvar), however I wasn't sure how to access it on the C side.