lua_tointegerx
lua_Integer d = lua_tointegerx(L, narg, &isnum);
l = (int)lua_tointegerx(L, -1, &isnum);
LUA_API lua_Integer (lua_tointegerx) (lua_State *L, int idx, int *isnum);
#define lua_tointeger(L,i) lua_tointegerx(L,i,NULL)