let rt_format_of_ctype t = match t with
| Ctypes.C_int c_int -> format_of_c_int_type c_int
| Ctypes.C_float c_float -> format_of_c_float_type c_float
| Ctypes.C_comp comp -> format_of_compinfo comp
| Ctypes.C_array arr -> format_of_array arr
| Ctypes.C_pointer ty -> format_of_addr ty