#include "Tutorial.h" void OneTutorial() { /// .`One` /// `One` is a container that can store none or one element of T or derived from T. It is /// functionally quite similar to `std::unique_ptr`, but has some convenient features. struct Base { virtual String Get() = 0; virtual ~Base() {} }; struct Derived1 : Base { virtual String Get() { return "Derived1"; } }; struct Derived2 : Base { virtual String Get() { return "Derived2"; } }; One s; /// `operator bool` of one returns true if it contains an element: DUMP((bool)s); /// s.Create(); DUMP((bool)s); DUMP(s->Get()); /// You can use `Is` to check if certain type is currently stored in `One`: DUMP(s.Is()); DUMP(s.Is()); DUMP(s.Is()); /// To get a pointer to the contained instance, use `operator~`: Base *b = ~s; DUMP(b->Get()); /// Clear method removes the element from One: s.Clear(); DUMP((bool)s); /// }