Class deep_unique_ptr

support/DeepCopy.h:59–151

 */
template <typename Base>
class deep_unique_ptr
{
public:
    using CopyFunc = std::function<Base *(const Base *)>;

    deep_unique_ptr(std::nullptr_t val = nullptr) noexcept : _val{val}, _copy{}
    {
    }
    template <typename Derived, typename CopyFuncDerived>
    deep_unique_ptr(Derived *value, const CopyFuncDerived &copy) noexcept : _val{value}, _copy{std::move(copy)}
    {
        static_assert(std::is_base_of<Base, Derived>::value, "Derived is not a specialization of Base");
        static_assert(std::is_constructible<CopyFunc, CopyFuncDerived>::value,
                      "CopyFuncDerived is not valid for a copy functor");
    }

    deep_unique_ptr(const deep_unique_ptr<Base> &ptr) : deep_unique_ptr(ptr.clone())
    {
    }
    deep_unique_ptr &operator=(const deep_unique_ptr<Base> &ptr)
    {
        deep_unique_ptr<Base> tmp(ptr);
        swap(*this, tmp);
        return *this;
    }

    deep_unique_ptr(deep_unique_ptr<Base> &&ptr)            = default;
    deep_unique_ptr &operator=(deep_unique_ptr<Base> &&ptr) = default;
    ~deep_unique_ptr()                                      = default;
    friend void swap(deep_unique_ptr &ptr0, deep_unique_ptr<Base> &ptr1) noexcept
    {
        using std::swap;
        swap(ptr0._val, ptr1._val);
        swap(ptr0._copy, ptr1._copy);
    }
    Base &operator*() noexcept
    {
        return *_val;
    }

    const Base &operator*() const noexcept
    {
        return *_val;
    }

    Base *operator->() noexcept
    {
        return _val.operator->();
    }

    const Base *operator->() const noexcept
    {
        return _val.operator->();
    }

    Base *get() noexcept
    {
        return _val.get();