std::out_ptr_t::~out_ptr_t(3)

💅 std::out_ptr_t::~out_ptr_t 💅

okay bestie, welcome to the destructor of std::out_ptr_t — yes, the one from the C++ Standard Library, and yes, it's giving quietly powerful 🎀

✨ NAME ✨

std::out_ptr_t::~out_ptr_t — literally the destructor of std::out_ptr_t, no notes 💅

🌸 Synopsis 🌸

~out_ptr_t();  (since C++23)

So here's the vibe: this destructor resets the adapted Smart object using the value of the modified Pointer object (or the void* object if operator void**() has been called) plus the captured arguments. That's the whole main character move, periodt 🫶

Let's define the cast, because we need the details:

• s denotes the adapted Smart object,
• args... denotes the captured arguments,
• p denotes the value of stored Pointer, or static_cast<Pointer>(*operator void**()) if operator void** has been called,
• SP be
  • Smart::pointer, if it is valid and denotes a type, otherwise,
  • Smart::element_type*, if Smart::element_type is valid and denotes a type, otherwise,
  • std::pointer_traits<Smart>::element_type*, if std::pointer_traits<Smart>::element_type is valid and denotes a type, otherwise,
  • Pointer.

ik, that's a whole chain of "otherwise" — it's giving choose-your-own-adventure 💀 but just follow it top to bottom and you'll land on the right type, trust.

If s.reset(static_cast<SP>(p), std::forward<Args>(args)...) is well-formed, the destructor performs:

if (p) s.reset(static_cast<SP>(p), std::forward<Args>(args)...);

otherwise, if std::is_constructible_v<Smart, SP, Args...> is true, the destructor performs:

if (p) s = Smart(static_cast<SP>(p), std::forward<Args>(args)...);

otherwise, the program is ill-formed. 😭 no cap, that's the hard stop — bestie, don't go there.

🦋 Notes 🦋

• If Smart is a std::shared_ptr specialization, the implementation may allocate the storage for the new control block on construction, in order to leave non-throwing works to the destructor. lowkey iconic of it ✨
• Arguments captured by value are destroyed after resetting. that's the order, respect it 🙈

💖 reminder: if (p) is doing a lot of heavy lifting in both branches — the reset/assign only happens when p is truthy. slay.

okay that's the whole page bestie, you ate that 🍓 — this was std::out_ptr_t::~out_ptr_t from the C++ Standard Library, brought to you by http://cppreference.com, dated 2024.06.10, and I hope your pointers stay out-ptr'd and your destructors stay well-formed 🌈👑💜