Function luaL_testudata

src/Chain/libraries/glua/lauxlib.cpp:326–338

LUALIB_API void *luaL_testudata(lua_State *L, int ud, const char *tname) {
    void *p = lua_touserdata(L, ud);
    if (p != nullptr) {  /* value is a userdata? */
        if (lua_getmetatable(L, ud)) {  /* does it have a metatable? */
            luaL_getmetatable(L, tname);  /* get correct metatable */
            if (!lua_rawequal(L, -1, -2))  /* not the same? */
                p = nullptr;  /* value is a userdata with wrong metatable */
            lua_pop(L, 2);  /* remove both metatables */
            return p;
        }
    }
    return nullptr;  /* value is not a userdata with a metatable */
}


LUALIB_API void *luaL_checkudata(lua_State *L, int ud, const char *tname) {