#include <iostream>

struct test
{
    test()
    {
        std::cout << "test ctor\n";
    }
    ~test()
    {
        std::cout << "test dtor\n";
    }
};

struct Data {
    Data(const test &data = {}) : data_(data) 
    {
        std::cout << "data ctor\n";
    }
    ~Data()
    {
        std::cout << "data dtor\n";
    }
    const test &data_;

    void forceuse()
    {
        std::cout << "Using data\n";
    }
};

Data create3(const test &data = {}) {
    std::cout << "in create3\n";
    return Data(data); // good
}

int main() {
    {
        std::cout << "calling create3\n";
        auto data3 = create3(); // ok
        std::cout << "returned from create3\n";
        data3.forceuse();
    }
}