void start(void) __attribute__ ((constructor)); static void stop(void) __attribute__ ((destructor...\n"); } __attribute__((destructor)) void unload_file() { printf("destructor is called.
CObject { public: CObject() { printf("CObject Constructor \n"); } ~CObject() { printf("CObject Destructor...: CCmdTarget() { printf("CCmdTarget Constructor \n"); } ~CCmdTarget() { printf("CCmdTarget Destructor...m_pCurrentWinApp = this; printf("CWinApp Constructor \n"); } ~CWinApp() { printf("CWinApp Destructor...public CWnd { public: CView() { printf("CView Constructor \n"); } ~CView() { printf("CView Destructor...//CWinApp Destructor //CWinThread Destructor //CCmdTarget Destructor //CObject Destructor 发布者：
C.35: A base class destructor should be either public and virtual, or protected and nonvirtual 基类的析构函数要么是公开的虚函数...If the destructor is public, then calling code can attempt to destroy a derived class object through...a base class pointer, and the result is undefined if the base class's destructor is non-virtual....If the destructor is protected, then calling code cannot destroy through a base class pointer and the...Note（注意） A destructor must be nonprivate or it will prevent using the type: 析构函数必须是非私有的，除了它不想被别人用。
C.30: Define a destructor if a class needs an explicit action at object destruction 如果一个类需要明确的销毁动作，...定义析构函数 Reason（原因） A destructor is implicitly invoked at the end of an object's lifetime....If the default destructor is sufficient, use it....Only define a non-default destructor if a class needs to execute code that is not already part of its...Example, bad（反面示例） class Foo { // bad; use the default destructor public: // ...
C.36: A destructor may not fail 析构函数不应该失败 Reason(原因) In general we do not know how to write error-free...code if a destructor should fail....The writer of a destructor does not know why the destructor is called and cannot "refuse to act" by throwing...Note（注意） Declare a destructor noexcept....Enforcement（实施建议） (Simple) A destructor should be declared noexcept if it could throw.
: Base(){ cout << "Base Constructor Called\n"; } ~Base(){ cout Destructor...(){ cout << "Derived constructor called\n"; } ~Derived1(){ cout destructor...输出如下： Base Constructor Called Derived constructor called Base Destructor called 我们发现派生类的析构函数并没有调用，这是有问题的...Base(){ cout << "Base Constructor Called\n"; } virtual ~Base(){ cout Destructor...called\n"; } }; 输出如下： Base Constructor Called Derived Constructor called Derived destructor called
C.127: A class with a virtual function should have a virtual or protected destructor C.127:包含虚函数的类应该有虚析构函数或保护析构函数...Less commonly, if deletion through a pointer to base is not intended to be supported, the destructor...Example, bad(反面示例) struct B { virtual int f() = 0; // ... no user-written destructor, defaults...to public nonvirtual ... }; // bad: derived from a class without a virtual destructor struct D : B...Flag delete of a class with a virtual function but no virtual destructor. 提示针对包含虚函数却没有虚析构函数的类的销毁操作。
Animal() { cout << "Animal constructor" << endl; } ~Animal() { cout destructor...public: Dog() { cout << "Dog constructor" << endl; } ~Dog() { cout destructor...由于 Animal 的析构函数不是虚拟的，所以仅调用了基类的析构函数： Animal constructor Dog constructor Animal destructor 可以看到，Dog 类的析构函数没有被调用...cout << "Animal constructor" << endl; } virtual ~Animal() { cout destructor...Animal destructor 在这种情况下，派生类 Dog 的析构函数正常地被调用。
C.37: Make destructors noexcept C.37:保证析构函数不会抛出异常 Reason(原因) A destructor may not fail....If a destructor tries to exit with an exception, it's a bad design error and the program had better terminate...By explicitly marking destructors noexcept, an author guards against the destructor becoming implicitly...struct X { Details x; // happens to have a throwing destructor // ......Enforcement（实施建议） (Simple) A destructor should be declarednoexceptif it could throw.
{ std::cout << "default construction" << std::endl; } ~X() { std::cout destructor.../main default construction destructor copy/move construction 都被省略..../main default construction copy constructor destructor copy constructor destructor destructor class
cout<<"this is A's constructor, num="<<num<<endl; } ~A(){ coutdestructor...} int main(){ try{ autoptrtest1(); } catch(int){ coutdestructor...endl; } cout<<endl; try{ autoptrtest2(); } catch(int){ coutdestructor...does be invoked"<<endl; } } 程序的输出结果： this is A’s constructor, num=1 there is no destructor invoked...this is A’s constructor, num=2 2 this is A’s destructor, num=2 A’s destructor does be invoked
() [0x7ffd94c8acb0] destructor() [0x7ffd94c8aca0] 1234567891011121314 这……没有任何区别啊，C++国际标准委员会逗我玩呢？...() [0x7ffe849b8a70] moving from [0x7ffe849b8ab0] to [0x7ffe849b8aa0] destructor() [0x7ffe849b8ab0] --...() [0x7ffe849b8ab0] destructor() [0x7ffe849b8aa0] 1234567891011121314151617 可以看到在step1中调用process函数的时候...] moving from [0x7ffe7d59f350] to [0x7ffe7d59f380] destructor() [0x7ffe7d59f350] destructor() [0x7ffe7d59f380...] moving from [0x7ffca4276e50] to [0x7ffca4276e90] destructor() [0x7ffca4276e50] destructor() [0x7ffca4276e90
; class C { int m; public: C(){ cout<<"in C constructor"<<endl;} ~C(){ coutdestructor...endl;} }; class A { public: A(){ cout<<"in A constructor"<<endl;} ~A(){ coutdestructor...resource=new char[100]; cout<<"in B constructor"<<endl; throw -1; } ~B() { coutdestructor...cout<<"catched"<<endl; } } 程序输出结果： in A constructor in C constructor in B constructor in C destructor...in A destructor catched 从输出结果可以看出，在构造函数中抛出异常，当前对象的析构函数不会被调用，如果在构造函数中分配了内存，那么会造成内存泄露，所以要格外注意。
cout<<"this is A's constructor, num="<<num<<endl; } ~A() { coutdestructor...{ try { uniqueptrtest1(); } catch(int) { coutdestructor...cout<<endl; try { uniqueptrtest2(); } catch(int) { coutdestructor...does be invoked"<<endl; } } 程序的输出结果： this is A's constructor, num=1 there is no destructor invoked...this is A's constructor, num=2 2 this is A's destructor, num=2 A's destructor does be invoked 在解读上面的这段程序的时候
<< endl; }; ~Father() { cout destructor Father!"...<< endl; }; ~Son() { cout destructor Son!"...<< endl; }; virtual ~Father() { cout destructor Father!"...<< endl; }; ~Son() { cout destructor Son!"...//destructor Son! //destructor Father!
args */) { cout<<"base class constructor called"<<endl; } base::~base() { coutdestructor...*/) { cout<<"class mid_a constructor called"<<endl; } mid_a::~mid_a() { coutdestructor...*/) { cout<<"class mid_b constructor called"<<endl; } mid_b::~mid_b() { coutdestructor...called class mid_b destructor called base class destructor called class mid_a destructor called base...class destructor called 分析：先尝试实例化mid_a，由于mid_a继承自base，因此调用了base的构造函数，然后调用mid_a的构造函数。
using namespace std; class C { int m; public: C(){cout<<"in C constructor"<<endl;} ~C(){coutdestructor..."<<endl;} }; class A { public: A(){cout<<"in A constructor"<<endl;} ~A(){coutdestructor"<<...{ resource=new char[100]; cout<<"in B constructor"<<endl; throw -1; } ~B() { coutdestructor...int) { cout<<"catched"<<endl; } } 程序输出结果： in A constructor in C constructor in B constructor in C destructor...in A destructor catched 从输出结果可以看出，在构造函数中抛出异常，当前对象的析构函数不会被调用，如果在构造函数中分配了内存，那么会造成内存泄露，所以要格外注意。
C.31: All resources acquired by a class must be released by the class's destructor 类申请的所有资源必须在析构函数释放...A destructor, close, or cleanup operation should never fail....For starters, the writer of a destructor does not know why the destructor is called and cannot "refuse...Obviously, such objects should not be deleted by the class's destructor....blob/master/CppCoreGuidelines.md#c31-all-resources-acquired-by-a-class-must-be-released-by-the-classs-destructor
//tmp destructor. //~localObj move constructor. //obj destructor....//~tmp destructor. //~obj 0x7ffff064f99f constructor....//tmp 0x7ffff064f99f destructor. //~localObj 0x7ffff064f9be move constructor....//obj 0x7ffff064f9bf destructor. //~tmp 0x7ffff064f9be destructor....//localObj 0x7fffb212e72f destructor.
class First { ~First() { Console.WriteLine("First's destructor...Second : First { ~Second() { Console.WriteLine("Second's destructor...Third : Second { ~Third() { Console.WriteLine("Third's destructor...Third t = new Third(); } } /* Output : Third's destructor...Second's destructor is called. First's destructor is called. */
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