A modest suggestion for the Lua 5.2 C API: luaL_checklightudata(L, narg)

[Sir Pogsalot <sir.pogsalot@...>]

/* to go in src/lauxlib.c */

LUALIB_API void *
checklightudata(lua_State *L, int narg)
{
    if (lua_islightuserdata(L, narg))
        luaL_typerror(L, narg, "lightuserdata");

    return lua_topointer(L, narg);
}

I felt that this was the only function missing from the luaL_check*()
functions.  The objective is to assert that a certain stack index is
lightuserdata and generate a type error if it isn't, otherwise return
the void * contained.

NOTE: I could not use tag_error() for consistency with the other
luaL_check*() functions.  If tag_error() were used and this were
called on an index containing userdata (not lightuserdata) it would
generate an error like this:

location: bad argument narg to 'func' (userdata expected, got userdata)

Please and thank you, Brasil :x