The code
USE ISO_C_BINDING, ONLY: C_PTR, C_LOC
REAl, TARGET ::A1
TYPE(C_PTR) :: D = C_LOC(A1)
yields the following error message
TYPE(c_ptr) :: D = C_LOC(A1)
1
Error: Function 'c_loc' in initialization expression at (1) must be an
intrinsic or a specification function
Obviously the manual currently describes C_LOC as an intrinsic and the
value of the expression is relatively known at compile time,
and the code could be compiled to cause the value to fixed by the
linker/loader.
Failing that, the error message ought to be
Error: Intrinsic function 'c_loc' at (1) is not permitted in an
initialization expression
