通过 BaseClass List 调用派生类对象的析构函数

Call Destructor of derived ClassObjects via BaseClass List

本文关键字:对象 析构函数 派生 BaseClass List 调用 通过      更新时间:2023-10-16

我让这个类来获取所有派生对象的列表

Register.h
-----------------
class Register {
...
public:
// static object list
static list<Register*> instances;
// default constructor for register object
Register::Register();
// virtual destructor to clean up with subobject destructor first
virtual Register::~Register();
// default methods for this class
static void Register::stop();
Register.cpp
-----------------
#include "Register.h"
// list with all object instances made by this programm
list<Register*> Register::instances;
// default destructor
Register::~Register() {
  list<Register*>::iterator p = find(instances.begin(), instances.end(), this);
  if (p != instances.end()) {
    instances.erase(p);
  }
}
// erase all instances clean up the dish
void Register::stop() {
  // last log message
  Log::write("register cleanup");
  // stops the logging object
  Log::stop();
  // clean up instances
  list<Register*>::iterator iter = instances.begin();
  list<Register*>::iterator end  = instances.end();
  while (iter != end) {
    cout<< endl << (*iter) -> typeName << endl;
    //delete *iter;
  }
  Register::instances.clear();
}

和派生类

File.h
-----------------
class File : public Register {
...
// default destructor
virtual File::~File(void);
...
}
File.cpp
-----------------
// default destructor
File::~File(void) {
  cout << "file destr";
  this -> deleteFile();
}
Log.h
-----------------
// this class implements a log handler
// (derived from register)
class Log : public File {
public:
  // singelton logging object
  static Log* log;
  // default destructor
  Log::~Log(void);
Log.cpp
-----------------
using namespace std;
// declare pointer for easy logging
Log* Log::log = NULL;
// default destructor
Log::~Log(void) {
cout << "log destr";
}

现在我想删除整个结构,只需删除列表和其中的对象。

我试过

 Main.cpp
-----------------
 int main (int argc, char *argv[], char *envp[]) {
   Register::stop();
   return 1;
 }

但对象仍被实例化

我没有想法^^

请。。

Register::instances.clear();

这将清除指针列表,但不对对象执行任何操作。在清除列表之前,您需要自己删除它们,例如像这样

for (list<Register *>::iterator it = Register::instances.begin();
     it != Register::instances.end();
     ++it) {
    delete *it;
}
Register::instances.clear();

作为手动清除列表的替代方法,C++11引入了与STL容器兼容的std::unique_ptr<>智能指针。

static std::list<std::unique_ptr<Register>> instances;

基本上会负责删除对象。

好的..我解决了它..

// clean up instances
list<Register*>::iterator iter = instances.begin();
list<Register*>::iterator end  = instances.end();
while (iter != end) {
  iter = instances.erase(iter);
}
Register::instances.clear();