template <typename R>
class ResourceManager
{
public:
    ResourceManager() = default;

    template <typename T>
    void set(const R& name, T& object);

    template <typename T>
    T get(const R& name);

private:
    QHash<R, void*> m_objectsMap;
};

template <typename R>
template <typename T>
void ResourceManager<R>::set(const R& name, T& object) {
    m_objectsMap.insert(name, reinterpret_cast<void*>(&object));
}

template <typename R>
template <typename T>
T ResourceManager<R>::get(const R& name) {
    auto it = m_objectsMap.find(name);

    if (it == m_objectsMap.end()) throw std::invalid_argument("The item doesn't exists");

    return *static_cast<T*>(it.value());
}

struct UserData {
    QString username = "";
    QString permissions = "";

    QString  token = "";
    qint64   lastTimeUsed = 0;

    UserData() {}
};

void f() {
    UserData userData;
    userData.username    = userStruct.username;
    userData.permissions = userStruct.permissions;
    userData.token       = token;
    userData.updateLastTimeUsed();

    qDebug() << "[Users][actionCheckToken]userData='" << userData.toString() << "'";

    client.getResourceManager()->set<UserData>(USER_RESOURCEMANAGER_USERDATA_KEY, userData);
}

1   std::__atomic_base<int>::load                  atomic_base.h       396 0x55555556500e
2   QAtomicOps<int>::load<int>                     qatomic_cxx11.h     227 0x55555556500e
3   QBasicAtomicInteger<int>::load                 qbasicatomic.h      103 0x555555563e5e
4   QtPrivate::RefCount::ref                       qrefcount.h         55  0x5555555624a6
5   QString::QString                               qstring.h           958 0x5555555629a9
6   Users::UserData::UserData <- my struct         Users.hpp           26  0x555555578cf1
7   ResourceManager<QString>::get<Users::UserData> ResourceManager.hpp 36  0x555555578df4
8   [function from where I call]

void b(Client& client) {
    qDebug() << "[Users][userIsLogged]Called" << "clientID='" + client.getID() + "'";

    auto userData = client.getResourceManager()->get<UserData>(USER_RESOURCEMANAGER_USERDATA_KEY);

    // ...
}