demo_copy_constructor_2.cpp

对于一个初涉VC＋＋的人来书

//***************************************************

# include <iostream.h>
# include <string.h>

class Student
{
public:
	Student(char* pName="no name") //构造函数
	{
		cout<<"Constructing new student "<<pName<<endl;

		strcpy(name,pName); 
	}

	Student(Student& s) //拷贝构造函数
	{
		cout<<"Constructing copy of "<<s.name<<endl;

		strcpy(name,s.name);
	}

	~Student() //析构函数
	{
		cout<<"Destructing "<<name<<endl;
	}

protected:
	char name[40];
};

class Tutor
{
public:
	Tutor(Student& s):student(s) //拷贝构造函数
	{
		cout<<"Constructing tutor"<<endl;
	}

protected:
	Student student;
};

void fn(Tutor tutor)
//void fn(Tutor& tutor)
{
	cout<<"    In function fn()"<<endl;
}

void main()
{
	Student jenny("Jenny");
	Tutor tutor(jenny);

	cout<<"    Calling fn()"<<endl;

	fn(tutor);

	cout<<"    Returned from fn()"<<endl;
}

/***1
Constructing new student Jenny
Constructing copy of Jenny
Constructing tutor
    Calling fn()
Constructing copy of Jenny
    In function fn()
Destructing Jenny
    Returned from fn()
Destructing Jenny
Destructing Jenny
/***2
Constructing new student Jenny
Constructing copy of Jenny
Constructing tutor
    Calling fn()
    In function fn()
    Returned from fn()
Destructing Jenny
Destructing Jenny
*/