一个C++构造函数，内存分配的例子

#include<stdio.h>#include<stdlib.h>#include<string.h>#include<iostream>using namespace std;class simpleclass{private:char *m_buf;int m_nSize;int *m_count;public:simpleclass(int n=1){m_buf=new char[n];m_nSize=n;m_count=new int;*m_count=1;cout<<"count is "<<*m_count<<endl;};simpleclass(const simpleclass &s){m_nSize=s.m_nSize;m_buf=s.m_buf;m_count=s.m_count;(*m_count)++;cout<<"count is "<<*m_count<<endl;};~simpleclass(){(*m_count)--;cout<<"count is "<<*m_count<<endl;if(*m_count==0){//cout <<m_nSize<<"is deleted at "<<m_buf<<endl;printf("%d is deleted at %xd\n",m_nSize,m_buf);delete[] m_buf;delete m_count;}};char *Getbuf(){return m_buf;};simpleclass& operator = (const simpleclass&s){if(m_buf==s.m_buf){return *this;}(*m_count)--;if(*m_count==0){m_nSize=s.m_nSize;m_buf=s.m_buf;m_count=s.m_count;(*m_count)++;}};};void foo(){simpleclass a;char *p=a.Getbuf();strcpy(p,"hello");cout <<p<<endl;simpleclass b=a;simpleclass c(20);c=a;//因为你在C申请的内存没有释放，所以出现内存泄漏cout<<"b="<<b.Getbuf()<<endl;printf("b=%s,c=%s\n",b.Getbuf(),c.Getbuf());}int main(){foo();printf("exit main()……\n");}