destroying operator delete - C++20 İle Geliyor

Giriş

Açıklaması şöyle

Prior to C++20, objects' destructors were always called prior to calling their operator delete. With destroying operator delete in C++20, operator delete can instead call the destructor itself.

Örnek

Elimizde şöyle bir kod olsun

#include <iostream>
#include <new>

struct Foo {
    ~Foo() {
        std::cout << "In Foo::~Foo()\n";
    }

    void operator delete(void *p) {
        std::cout << "In Foo::operator delete(void *)\n";
        ::operator delete(p);
    }
};

struct Bar {
    ~Bar() {
        std::cout << "In Bar::~Bar()\n";
    }

    void operator delete(Bar *p, std::destroying_delete_t) {
        std::cout << "In Bar::operator delete(Bar *, std::destroying_delete_t)\n";
        p->~Bar();
        ::operator delete(p);
    }
};

int main() {
    delete new Foo;
    delete new Bar;
}

Çıktı olarak şunu alırız

In Foo::~Foo()
In Foo::operator delete(void *)
In Bar::operator delete(Bar *, std::destroying_delete_t)
In Bar::~Bar()