cnfMalloc is automatically registered using this
The function attempts to register a C pointer so that it may be used from both C and FORTRAN. If
successful, registration subsequently allows the pointer to be converted into a FORTRAN pointer of
type F77_POINTER_TYPE (using
cnfFptr), and then back into a C pointer (using
conversions are possible even if the FORTRAN pointer is stored in a shorter data type than the C
Not all C pointers may be registered, and registration may fail if the FORTRAN version of the pointer is indistinguishable from that of a pointer which has already been registered. In such a case, a new C pointer must be obtained (e.g. by allocating a different region of memory).
If an internal error occurs (e.g. if insufficient memory is available), the function returns -1.