类型转换构造函数

目的：

实现类型的自动转换

特点：

• 只有一个参数
• 不是复制构造函数

#include<stdio.h>
#include<stdlib.h>
#include<iostream>
using namespace std;
class complex{
    private:
        double real,imag;
    public:
        complex(int i)//类型转换构造函数 
        {
            cout<<"Intconstructor is called"<<endl;
            real=i;
            imag=0;
        }
        complex()
        {
        cout<<"no parameter constructor is called"<<endl;   
        }
        complex(double x,double y)
        {
        real=x;
        imag=y; 
        cout<<"constructor is called"<<endl;
        }
        complex(const complex&c)
        {
            real=c.real;
            imag=c.imag;
            cout<<"copy constuctor is called."<<endl;
        }
        void get_complex()
        {
        cout<<real<<"+"<<imag<<"i"<<endl;   
        }   
};
complex fun()
{
    complex a(1,2);
    return a;
}
int main()
{
    complex c1(7,8);
    complex c2=12;//初始化语句,直接调用complex(int)初始化c2 
    c1=9;//赋值语句，9被自动转化为一个临时的complex对象，然后将临时对象的值赋值给c1 
    c1.get_complex();
    return 0;
}

程序结果：

constructor is called
Intconstructor is called
Intconstructor is called
9+0i