I get these warnings with each corresponding line. How do I get rid of them?
62 C:\projects\spacedout\midi.c
[Warning] comparison between pointer and integer
if(midi->device_handle == NULL)
68 C:\projects\spacedout\midi.c
[Warning] assignment makes integer from pointer without a cast
midi->device_handle = NULL;
>midi->device_handle
Are you sure that this is a pointer?
My best code is written with the delete key.
more liklely to be an integer.
Then am I suppose to change NULL to 0? I thought NULL is 0.
NULL is more likely to be (void*)0. But if the variable is an int you should use 0, if it's a pointer you should use NULL. It's a bad idea to try and use NULL in any context other than pointers.Then am I suppose to change NULL to 0? I thought NULL is 0.
Yes, that is a pointer. "midi" is the address of a structure, and "device_handle" is a field in the structure. Which also happens to be the address of a structure for a device record.Code:if(midi->device_handle == NULL)
Since it is a pointer, you must use "(void*)0L", to explicitly tell the compiler to ignore the coercion/cast.
If necessary make a headerfile for yourself with your own global defines, and do something like this:
That makes sure that you have a value that is zero across all bits of the native word, and can be used with pointers.Code:#define NIL (void*)0L
enjoy.
It is not the spoon that bends, it is you who bends around the spoon.
