tencent cloud

[V2TIMManager.sharedInstance findMessages:messageIDList
                                        succ:^(NSArray<V2TIMMessage *> *msgs) {
    // Messages queried successfully
} fail:^(int code, NSString *desc) {
    // Failed to query the messages
}];

template <class T>
class ValueCallback final : public V2TIMValueCallback<T> {
public:
    using SuccessCallback = std::function<void(const T&)>;
    using ErrorCallback = std::function<void(int, const V2TIMString&)>;

    ValueCallback() = default;
    ~ValueCallback() override = default;

    void SetCallback(SuccessCallback success_callback, ErrorCallback error_callback) {
        success_callback_ = std::move(success_callback);
        error_callback_ = std::move(error_callback);
    }

    void OnSuccess(const T& value) override {
        if (success_callback_) {
            success_callback_(value);
        }
    }
    void OnError(int error_code, const V2TIMString& error_message) override {
        if (error_callback_) {
            error_callback_(error_code, error_message);
        }
    }

private:
    SuccessCallback success_callback_;
    ErrorCallback error_callback_;
};

auto callback = new ValueCallback<V2TIMMessageVector>{};
callback->SetCallback(
    [=](const V2TIMMessageVector& messageVector) {
        // Messages queried successfully
        delete callback;
    },
    [=](int error_code, const V2TIMString& error_message) {
        // Failed to query the messages
        delete callback;
    });

V2TIMManager::GetInstance()->GetMessageManager()->FindMessages(messageIDList, callback);