Re: generic imports? void* -> generics?

[Jeffrey Carter <spam@spam.com>]

Matthew Heaney wrote:

>    function To_Userdata
>      (L : lua_state_access;
>       Pos : Index) return Userdata is
> 
>       type Userdata_Access is access all Userdata;
>       for Userdata_Access'Storage_Size use 0;
>       pragma Convention (C, Userdata_Access);
> 
>       function lua_touserdata
>         (L   : Lua_State_Access;
>          Pos : C.int) return Userdata_Access;  --ok now
> 
>       pragma Import (C, lua_touserdata);

You probably need to specify the C name:

pragma Import (C, lua_touserdata, "lua_touserdata");

>       pragma Convention (C, lua_touserdata);

This is unnecessary. Import defines the convention.

> 
>       Result : constant Userdata_Access :=
>          lua_touserdata(L, Pos);
>    begin
>       return Result.all;
>    end;

Or just

return Lua_Touserdata (L, Pos).all;

This is probably the best way to implement it; I was going to suggest 
something along these lines until I saw this. Of course, this would be a 
generic, with type Userdata the generic formal.

-- 
Jeff Carter
"You've got the brain of a four-year-old boy,
and I bet he was glad to get rid of it."
Horse Feathers
47