Macro to obtain kind parameter value in F90?

[Rhys Ulerich]

Can anyone recommend a macro for obtaining a kind parameter value in
Fortran 90?  Or a macro where I might look for how to roll my own?

The check would be like AC_SIZEOF, but instead of returning the size
it would return the kind parameter value (an integer).  AC_COMPUTE_INT
would be perfect, but it appears to not work inside
AC_LANG_PUSH([Fortran])/AC_LANG_POP([Fortran]) due to an error like
'AC_LANG_BOOL_COMPILE_TRY: unknown language: Fortran'.

For the curious, I want the value so that I can wrap a C
implementation with a public Fortran API that exposes types like
REAL(4) instead of REAL(C_FLOAT).  The latter "leaks" ISO_C_BINDING
information to clients while the former does not.

- Rhys