std::unique...~unique_ptr(3)

💅 std::unique_ptr::~unique_ptr 💅

okay so this page is std::unique...~unique_ptr(3) from the C++ Standard Libary manual, and it’s literally about the destructor. cleanup main character energy, no cap 🧹✨

✨ NAME ✨

std::unique_ptr::~unique_ptr — std::unique_ptr::~unique_ptr

bestie, that’s the whole name. slay. 💅

🌸 Synopsis 🌸

~unique_ptr();  (since C++11)
                (constexpr since C++23)

okay so here’s the vibe check: if get() == nullptr, there are no effects. periodt. otherwise, the owned object is destroyed via get_deleter()(get()).

and this is a hard requirement, not a suggestion: get_deleter()(get()) must not throw exceptions. like, fr fr, don’t do it. 🫶

📝 Notes 📝

here’s the tea: although std::unique_ptr<T> with the default deleter may be constructed with an incomplete type T, the type T must be complete at the point of code where the destructor is called. so like… construction said “we can work with this,” but destruction is where the type has to be fully there. no skipping, bestie. 😭✨

🧚 Example 🧚

the following program demonstrates usage of a custom deleter. it’s giving “watch me clean up with style” 🔥

the original has a little // Run this code marker before the program, so here’s that and then the code:

#include <iostream>
#include <memory>

int main ()
{
    auto deleter = [](int* ptr)
    {
        std::cout << "[deleter called]\n";
        delete ptr;
    };

    std::unique_ptr<int, decltype(deleter)> uniq(new int, deleter);
    std::cout << (uniq ? "not empty\n" : "empty\n");
    uniq.reset();
    std::cout << (uniq ? "not empty\n" : "empty\n");
}

💖 Output 💖

not empty
[deleter called]
empty

this page came from http://cppreference.com, dated 2024.06.10, and its page name is std::unique...~unique_ptr(3) — mwah, bye bestie 🫶💜🎀