Is there a way to enforce explicit cast for typedefs of the same type? I've to deal with utf8 and sometimes I get confused with the indices for the character count and the byte count. So it be nice to have some typedefs:
typedef unsigned int char_idx_t;
typedef unsigned int byte_idx_t;
With the addition that you need an explicit cast between them:
char_idx_t a = 0;
byte_idx_t b;
b = a; // compile warning
b = (byte_idx_t) a; // ok
I know that such a feature doesn't exist in C, but maybe you know a trick or a compiler extension (preferable gcc) that does that.
EDIT I still don't really like the Hungarian notation in general. I couldn't use it for this problem because of project coding conventions, but I used it now in another similar case, where also the types are the same and the meanings are very similar. And I have to admit: it helps. I never would go and declare every integer with a starting "i", but as in Joel's example for overlapping types, it can be life saving.
For "handle" types (opaque pointers), Microsoft uses the trick of declaring structures and then typedef'ing a pointer to the structure:
#define DECLARE_HANDLE(name) struct name##__ { int unused; }; \
typedef struct name##__ *name
Then instead of
typedef void* FOOHANDLE;
typedef void* BARHANDLE;
They do:
DECLARE_HANDLE(FOOHANDLE);
DECLARE_HANDLE(BARHANDLE);
So now, this works:
FOOHANDLE make_foo();
BARHANDLE make_bar();
void do_bar(BARHANDLE);
FOOHANDLE foo = make_foo(); /* ok */
BARHANDLE bar = foo; /* won't work! */
do_bar(foo); /* won't work! */