namespace std {
template <class T> struct default_delete {
constexpr default_delete() noexcept = default;
template <class U> default_delete(const default_delete<U>&) noexcept;
void operator()(T*) const;
};
} template <class U> default_delete(const default_delete<U>& other) noexcept;
void operator()(T* ptr) const;
namespace std {
template <class T> struct default_delete<T[]> {
constexpr default_delete() noexcept = default;
template <class U> default_delete(const default_delete<U[]>&) noexcept;
template <class U> void operator()(U* ptr) const;
};
}template <class U> default_delete(const default_delete<U[]>& other) noexcept;
template <class U> void operator()(U* ptr) const;