← Back to context

Comment by wavemode

12 hours 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.

5 comments

wavemode

Reply
procaryote  11 hours ago

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

typedef struct foo foo;

and somewhere else

struct foo { … }

flohofwoe  6 hours 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 :)

  • apaprocki  3 hours 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

    • 1718627440  35 minutes ago

      Why are you complicating things? Struct and Unions are different namespaces for a reason.

          typedef struct GtkLabel GtkLabel;

      works just fine.

  • warmwaffles  2 hours 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.