c++: inheritance lambda ref https://www.youtube.com/watch?v=W-xTpqj31mI&feature=share

inheritance.cpp

template<typename L1, typename L2>
struct S : L1, L2
{
    S(L1 l1, L2 l2) :L1( std::move(l1) ), L2( std::move(l2) )
    {

    }
    using L1::operator();
    using L2::operator();
};

template<typename L1, typename L2>
auto make_combined(L1&& l1, L2 && l2) {
    return S<std::decay_t<L1>,  std::decay_t<L2>>(std::forward<L1>(l1), std::forward<L2>(l2));
}

int main()
{

    auto l1 = []() {return 10; };
    auto l2 = [](int x) {return x*x; };

  
    // auto combined = S(l1, l2); // this compile in gcc7 using c++17  class template deduction
    auto combined = S<decltype(l1), decltype(l2)>(l1, l2);
    auto combined2 = make_combined(l1, l2);
    return combined(10) + combined() + combined2(20) + combined2();
}