C++拷贝构造函数中的陷阱

#include<iostream>
using namespace std;
class CExample
{
public:
int a,b,c;
char *str;
public:
//构造函数
    CExample(int tb)
    {
        a = tb;
        b = tb+1;
        c = tb+2;
        str=(char *)malloc(sizeof(char)*10);
strcpy(str,"123456789");
cout<<"creat: "<<endl;
    }
 
//析构函数
    ~CExample()
    {
cout<< "delete: "<<endl;
    }
void Show ()
{
cout<<a<<endl;
    }
//拷贝构造
//CExample(const CExample& C)
//{
//    str=(char *)malloc(sizeof(char)*10);
//    strcpy(str,C.str);
//    cout<<"copy"<<endl;
//}
};
//全局函数，传入的是对象
void g_Fun(CExample C)
{
    C.a=0;C.b=0;C.b=0;
strcpy(C.str,"aaabbbccc");
cout<<"test"<<endl;
}
int main()
{
CExample test(1);
cout<<"str:"<<test.str<<" a="<<test.a<<" b="<<test.b<<" c="<<test.c<<endl;
    g_Fun(test);//传入对象
cout<<"str:"<<test.str<<" a="<<test.a<<" b="<<test.b<<" c="<<test.c<<endl;
    getchar();
return 0;
}

class CExample
{
int a,b,c;
};

class CExample
{
int a,b,c;
char *str;
};

CExample(const CExample& C)
{
    a=C.a;b=C.b;c=C.b;
    str=(char *)malloc(sizeof(char)*10);
strcpy(str,C.str);
cout<<"copy"<<endl;
}