[Users] best way to maintain CCTK_COMPLEX precision with Fortran?

Hi all.

The Cactus documentation shows a set of C routines CCTK_CmplxXXXXXX that presumably preserve precision between CCTK_REAL and CCTK_COMPLEX types. Is there a "right" way to handle this in Cactus with Fortran (that isn't "recode in C")?

Context: I have some Fortran code in a Cactus thorn that works with real & complex fields. I've noticed that when the numbers are very large in magnitude, taking a simple real(z) drops precision --- a finite but large real part ends up as +/- Inf instead. I suspect it's dropping to single precision at some stage. Switching to "dreal" doesn't help, and avoiding the use of CCTK_COMPLEX altogether --- while possible --- leads to longer, less readable code.

Thanks,

Bernard