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

typedef struct foo foo;

and somewhere else

struct foo { … }

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 :)