Comment by maccard

In C++ you can do: struct Foo { private: int val = 0; Foo(int newVal) : val(newVal) {} public: static optional<Foo> CreateFoo(int newVal) { if (newVal != SENTINEL_VALUE) { return Foo(newVal); } return {}; } };

    int main(int argc, char* argv[]) {
      if (auto f = CreateFoo(argc)) {
        cout << "Foo made with value " << f.val;
      } else {
        cout << "Foo not made";
      }
    }