arrayoperatornew.cpp

ThinkingC++中文版

//: C13:ArrayOperatorNew.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 2000
// Copyright notice in Copyright.txt
// Operator new for arrays
#include <new> // Size_t definition
#include <iostream>
using namespace std;

class Widget {
private:
	enum { sz = 10 };
    int i[sz];
public:
	Widget() 
	{ 
		cout << "Widget()"; 
	}
    ~Widget() 
	{ 
		cout << "~Widget()"; 
	}
    void* operator new(size_t sz) 
	{
       cout << "Widget::new: " << sz << " bytes" << endl;
       return ::new char[sz];
	}
    void operator delete(void* p) 
	{
        cout << "Widget::delete" << endl;
       ::delete []p;
	}
    void* operator new[](size_t sz) 
	{
		cout << "Widget::new[]: " << sz << " bytes" << endl;
        return ::new char[sz];
	}
    void operator delete[](void* p) 
	{
		cout << "Widget::delete[]" << endl;
		::delete []p;
	}
};

void main() 
{
  cout << "new Widget" << endl;
  Widget* w = new Widget;
  cout << "\ndelete Widget" << endl;
  delete w;
  cout << "\nnew Widget[25]" << endl;
  Widget* wa = new Widget[25];
  cout << "\ndelete []Widget" << endl;
} ///:~