Comment by wavemode

16 days ago

The main thing I dislike about typedefs is that you can't forward declare them.

If I know for sure I'm never going to need to do that then OK.

7 comments

wavemode

Reply
procaryote  16 days ago

How do you mean? You can at least do things like

typedef struct foo foo;

and somewhere else

struct foo { … }

flohofwoe  16 days ago

The usual solution for this is:

    typedef struct bla_s { ... } bla_t;

Now you have a struct named 'bla_s' and a type alias 'bla_t'. For the forward declaration you'd use 'bla_s'.

Using the same name also works just fine, since structs and type aliases live in different namespaces:

    typedef struct bla_t { ... } bla_t;

...also before that topic comes up again: the _t postfix is not reserved in the C standard :)

  • warmwaffles  16 days ago

    People getting hung up on `_t` usage being reserved for posix need to lighten up. I doubt they'll clash with my definitions and if does happen in the future, I'll change the typedef name.

  • apaprocki  16 days ago

    Yes, using the same Gtk example, the way you’d forward declare GtkLabel without including gtklabel.h in your header would be:

        struct _GtkLabel;
    typedef struct _GtkLabel GtkLabel;
    // Use GtkLabel* in declarations