It does for C# (see code below) but not for C++. using System; class Test { Test() { throw new Exception(); } ~Test() { Console.WriteLine(“Finalized”); } static void Main() { try { new Test(); } catch {} GC.Collect(); GC.WaitForPendingFinalizers(); } } This prints “Finalized”
Global and function static objects will get their destructors called when your application is exiting. these destructors are “exit time destructors”. and are called in the reverse order that they were constructed in. As you said, if some of these destructors touch already destroyed objects, your program could crash. Also, destructors running at exit time … Read more
You SHOULD NOT throw an exception out of a destructor. Note: Updated to refeclt changes in the standard: In C++03 If an exception is already propagating then the application will terminate. In C++11 If the destructor is noexcept (the default) then the application will terminate. The Following is based on C++11 If an exception escapes … Read more
The answer is no, because of the definition of “lifetime” in §3.8/1: The lifetime of an object of type T ends when: — if T is a class type with a non-trivial destructor (12.4), the destructor call starts, or — the storage which the object occupies is reused or released. As soon as the destructor … Read more
std::vector and std::strings: Are they destroyed automatically? Yes (assuming member variables are not pointers to std::vector and std::string). If I have something like std::vector what happens when the vector destructor is called? Would it call automatically the destructor of myClass? Or only the vector is destroyed but all the Objects it contains are still existant … Read more
If you have an object which should never, ever be deleted or stored on the stack (automatic storage), or stored as part of another object, =delete will prevent all of these. struct Handle { ~Handle()=delete; }; struct Data { std::array<char,1024> buffer; }; struct Bundle: Handle { Data data; }; using bundle_storage = std::aligned_storage_t<sizeof(Bundle), alignof(Bundle)>; std::size_t … Read more
The C++ Standard says: On exit from a scope (however accomplished), destructors (12.4) are called for all constructed objects with automatic storage duration (3.7.2) (named objects or temporaries) that are declared in that scope, in the reverse order of their declaration. So the answer is “yes”.
Yes, the QObject::~QObject destructor takes care of that: All signals to and from the object are automatically disconnected, and any pending posted events for the object are removed from the event queue. However, it is often safer to use deleteLater() rather than deleting a QObject subclass directly. Do take care though: Warning: Deleting a QObject … Read more
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. Here’s a very simple toy example of non-destroying vs. destroying operator delete: #include <iostream> #include <new> struct Foo { ~Foo() { std::cout << “In Foo::~Foo()\n”; } void … Read more
The order is: Base constructor Derived constructor Derived destructor Base destructor Example: class B { public: B() { cout<<“Construct B”<<endl; } virtual ~B() { cout<<“Destruct B”<<endl; } }; class D : public B { public: D() { cout<<“Construct D”<<endl; } virtual ~D() { cout<<“Destruct D”<<endl; } }; int main(int argc, char **argv) { D d; … Read more