Function lua_setmetatable

src/Chain/libraries/glua/lapi.cpp:848–885

LUA_API int lua_setmetatable(lua_State *L, int objindex) {
    TValue *obj;
    Table *mt;
    lua_lock(L);
    api_checknelems(L, 1);
    obj = index2addr(L, objindex);
    if (ttisnil(L->top - 1))
        mt = nullptr;
    else {
        api_check(L, ttistable(L->top - 1), "table expected");
        mt = hvalue(L->top - 1);
    }
    switch (ttnov(obj)) {
    case LUA_TTABLE: {
        hvalue(obj)->metatable = mt;
        if (mt) {
            luaC_objbarrier(L, gcvalue(obj), mt);
            luaC_checkfinalizer(L, gcvalue(obj), mt);
        }
        break;
    }
    case LUA_TUSERDATA: {
        uvalue(obj)->metatable = mt;
        if (mt) {
            luaC_objbarrier(L, uvalue(obj), mt);
            luaC_checkfinalizer(L, gcvalue(obj), mt);
        }
        break;
    }
    default: {
        G(L)->mt[ttnov(obj)] = mt;
        break;
    }
    }
    L->top--;
    lua_unlock(L);
    return 1;
}


LUA_API void lua_setuservalue(lua_State *L, int idx) {