destructor

问题 Switching from CUDA 8.0 to CUDA 9.0 RC, I get a warning about: __host__ __device__ ~Foo() = default; The warning is: path/to/Foo.cuh(69): warning: __host__ annotation on a defaulted function("~Foo") is ignored which I didn't use to get before. Should I really be getting this warning? What's wrong with indicating you want the default destructor on both the device and the host side? 回答1: What's wrong with indicating you want the default destructor on both the device and the host side? But that

问题 How can i simulate an OnDestroy event for a TFrame in Delphi? i nievely added a constructor and destructor to my frame, thinking that is what TForm does: TframeEditCustomer = class(TFrame) ... public constructor Create(AOwner: TComponent); override; destructor Destroy; override; ... end; constructor TframeEditCustomer.Create(AOwner: TComponent) begin inherited Create(AOwner); //allocate stuff end; destructor TframeEditCustomer.Destroy; begin //cleanup stuff inherited Destroy; end; The problem

问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed last year . Java has its own garbage collection implementation so it does not require any destructor like C++ . This makes Java developer lazy in implementing memory management. Still we can have destructor along with garbage collector where developer can free resources and which can save

问题 Is this program well-defined, and if not, why exactly? #include <iostream> #include <new> struct X { int cnt; X (int i) : cnt(i) {} ~X() { std::cout << "destructor called, cnt=" << cnt << std::endl; if ( cnt-- > 0 ) this->X::~X(); // explicit recursive call to dtor } }; int main() { char* buf = new char[sizeof(X)]; X* p = new(buf) X(7); p->X::~X(); // explicit call to dtor delete[] buf; } My reasoning: although invoking a destructor twice is undefined behavior, per 12.4/14, what it says

问题 Is this program well-defined, and if not, why exactly? #include <iostream> #include <new> struct X { int cnt; X (int i) : cnt(i) {} ~X() { std::cout << "destructor called, cnt=" << cnt << std::endl; if ( cnt-- > 0 ) this->X::~X(); // explicit recursive call to dtor } }; int main() { char* buf = new char[sizeof(X)]; X* p = new(buf) X(7); p->X::~X(); // explicit call to dtor delete[] buf; } My reasoning: although invoking a destructor twice is undefined behavior, per 12.4/14, what it says

问题 I have 2 classes: DataObject and DataElement . DataObject holds pointers to (only) DataElement s, and a DataElement contains pointers to several types, among which a DataObject . This used to be no problem, since I only use pointers to DataObject s in DataElement , so a forward declaration of DataObject in the header of DataElement is enough. Now, however, I try to add a destructor to DataElement , in which I need a delete on a DataObject . On this the compiler says: dataelement/destructor.cc

问题 I am wondering why after I invoke Free method the object is not nil . What I mean for example next class: type Ta = class(TObject) public i: integer; destructor Destroy; override; end; destructor Ta.Destroy; begin inherited; end; procedure Form1.Button1; var a: Ta; begin a := Ta.Create; a.Free; if a = nil then button1.Caption := 'is assigned' else button1.caption := 'is not assigned'; end; My question is why after freeing the object is not nil and how will I make a to be nil after destructor

问题 While doing my programming assignments, I seem to be stumbling over basic C++ concepts. I found the bug in my program and it was caused by my destructor running more times than I expected. Here is a code sample demonstrating what I am doing wrong, down to the bare essentials. #include <iostream> using namespace std; class A { public: A(int num) { number = num; cout << "A constructed with number " << number << ".\n"; } ~A() { cout << "A destructed with number " << number << ".\n"; } private:

问题 Can anybody explain to me the difference between Complex a; and Complex b(); ? #include<iostream> class Complex { public: Complex() { std::cout << "Complex Constructor 1" << std::endl; } Complex(float re, float im) { std::cout << "Complex Constructor 2" << std::endl; } ~Complex() { std::cout << "Complex Destructor" << std::endl; } }; int main() { Complex a; std::cout << "--------------------------" << std::endl; Complex b(); std::cout << "--------------------------" << std::endl; Complex c(0

问题 Can anybody explain to me the difference between Complex a; and Complex b(); ? #include<iostream> class Complex { public: Complex() { std::cout << "Complex Constructor 1" << std::endl; } Complex(float re, float im) { std::cout << "Complex Constructor 2" << std::endl; } ~Complex() { std::cout << "Complex Destructor" << std::endl; } }; int main() { Complex a; std::cout << "--------------------------" << std::endl; Complex b(); std::cout << "--------------------------" << std::endl; Complex c(0