23 General utilities library [utilities]

23.11 Smart pointers [smartptr]

23.11.1 Class template unique_­ptr [unique.ptr]

23.11.1.5 unique_­ptr specialized algorithms [unique.ptr.special]

template <class T, class D> void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;

Remarks: This function shall not participate in overload resolution unless is_­swappable_­v<D> is true.

Effects: Calls x.swap(y).

template <class T1, class D1, class T2, class D2> bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);

Returns: x.get() == y.get().

template <class T1, class D1, class T2, class D2> bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);

Returns: x.get() != y.get().

template <class T1, class D1, class T2, class D2> bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);

Requires: Let CT denote

common_type_t<typename unique_ptr<T1, D1>::pointer,
              typename unique_ptr<T2, D2>::pointer>

Then the specialization less<CT> shall be a function object type that induces a strict weak ordering on the pointer values.

Returns: less<CT>()(x.get(), y.get()).

Remarks: If unique_­ptr<T1, D1>​::​pointer is not implicitly convertible to CT or unique_­ptr<T2, D2>​::​pointer is not implicitly convertible to CT, the program is ill-formed.

template <class T1, class D1, class T2, class D2> bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);

Returns: !(y < x).

template <class T1, class D1, class T2, class D2> bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);

Returns: y < x.

template <class T1, class D1, class T2, class D2> bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);

Returns: !(x < y).

template <class T, class D> bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept; template <class T, class D> bool operator==(nullptr_t, const unique_ptr<T, D>& x) noexcept;

Returns: !x.

template <class T, class D> bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept; template <class T, class D> bool operator!=(nullptr_t, const unique_ptr<T, D>& x) noexcept;

Returns: (bool)x.

template <class T, class D> bool operator<(const unique_ptr<T, D>& x, nullptr_t); template <class T, class D> bool operator<(nullptr_t, const unique_ptr<T, D>& x);

Requires: The specialization less<unique_­ptr<T, D>​::​pointer> shall be a function object type that induces a strict weak ordering on the pointer values.

Returns: The first function template returns less<unique_­ptr<T, D>​::​pointer>()(x.get(),
nullptr)
. The second function template returns less<unique_­ptr<T, D>​::​pointer>()(nullptr, x.get()).

template <class T, class D> bool operator>(const unique_ptr<T, D>& x, nullptr_t); template <class T, class D> bool operator>(nullptr_t, const unique_ptr<T, D>& x);

Returns: The first function template returns nullptr < x. The second function template returns x < nullptr.

template <class T, class D> bool operator<=(const unique_ptr<T, D>& x, nullptr_t); template <class T, class D> bool operator<=(nullptr_t, const unique_ptr<T, D>& x);

Returns: The first function template returns !(nullptr < x). The second function template returns !(x < nullptr).

template <class T, class D> bool operator>=(const unique_ptr<T, D>& x, nullptr_t); template <class T, class D> bool operator>=(nullptr_t, const unique_ptr<T, D>& x);

Returns: The first function template returns !(x < nullptr). The second function template returns !(nullptr < x).