Provide example of providing a lifetime parameter

[metasim]

I tried to use the generics support in foreign_types like this:

foreign_type! {
    pub unsafe type Feature<'a> {
        type CType = libc::c_void;
        type PhantomData = 'a;
        fn drop = feature_dtor;
    }
}

The compiler error I get is:

error: at least one trait is required for an object type
  --> src/foo/bar.rs:21:28
   |
21 |         type PhantomData = 'a;
   |                            ^^

Is there some other way of doing this using the macro? Or maybe I'm using it incorrectly?

[sfackler]

'a is a lifetime, not a type. See here for example of using &'a (): https://docs.rs/foreign-types/latest/foreign_types/macro.foreign_type.html#examples

[metasim]

@sfackler Perfect! Apologies for missing that example. Much appreciated.