17~C++ new和delete运算符重载

重载 class A的new/delete 以及 new[]/delete[]运算符：
成功返回非空指针，失败返回空指针

#include <iostream>
#include <cstdlib>
using namespace std;
class A {
public:
	A (int var = 0) : m_var (var) {
		cout << "A构造：" << this << endl;
	
	}
	~A (void) {
		cout << "A析构：" << this << endl;
	}
	static void* operator new (size_t size) {
		void* pv = malloc (size);
		cout << "new：" << size << ' ' << pv
			<< endl;
		return pv;
	}
	static void operator delete (void* pv) {
		cout << "delete：" << pv << endl;
		free (pv);
	}
	static void* operator new[] (size_t size){
		void* pv = malloc (size);
		cout << "new[]：" << size << ' ' << pv
			<< endl;
		return pv;
	}
	static void operator delete[] (void* pv) {
		cout << "delete[]：" << pv << endl;
		free (pv);
	}
private:
	int m_var;
	string m_str;
};
int main (void) {
	A* pa = new A (100);
//	A* pa = (A*)A::operator new (sizeof (A));
//	A::A (pa, 100);
	cout << "pa = " << pa << endl;
	delete pa;
//	A::~A (pa);
//	A::operator delete (pa);
	pa = new A[5] {200, 300, 400, 500, 600};
	cout << "pa = " << pa << endl;
	cout << *((int*)pa-1) << endl;
	delete[] pa;
//	delete pa;
//	cout << 2 > 1 << endl;
	cout << (2 > 1) << endl;
	return 0;
}

来源：CSDN

作者：Johhny Rade

链接：https://blog.csdn.net/uncle103/article/details/103813323