#include<stdlib.h>
#include<string.h>
class image
{
public:
image(); //默认构造函数
image(int _height, int _width, int _channal);//带参数构造函数
~image(); //析构函数
image(const image& other);//拷贝构造函数
image& operator=(const image& other);//赋值操作符重载
private:
int height; //私有成员
int width;
int channal;
unsigned char *data;
};
image::image()
{
height = 0;
width = 0;
channal = 0;
data = NULL;
}
image::image(int _height, int _width, int _channal)
{
height = _height;
width = _width;
channal = _channal;
int total = height*width*channal;
data = new unsigned char[total]();
}
image::image(const image& other)
{
height = other.height;
width = other.width;
channal = other.channal;
int total = height*width*channal;
data = new unsigned char[total](); //深拷贝
memcpy(data, other.data, sizeof(unsigned char)*total);
}
image& image::operator=(const image& other)
{
height = other.height;
width = other.width;
channal = other.channal;
int total = height*width*channal;
if (data) //清除原有存储空间
delete[] data;
data = new unsigned char[total]();//重分配存储空间，深拷贝
memcpy(data, other.data, sizeof(unsigned char)*total);
return *this;
}
image::~image()
{
if (data)
delete[] data;
}
image test(image tmp) //测试拷贝构造函数，输入时会调用拷贝构造函数初始化形参tmp
{ //return时会调用拷贝构造函数初始化一个临时image对象
return tmp;
}
int main()
{
image a; //调用默认构造函数
image b(32, 32, 3);//调用带参数构造函数，初始化32*32的三通道图像，初始值都为0
a = b;//调用赋值操作符重载函数，深拷贝
image c = b;//调用拷贝构造函数，深拷贝
image d(b); //调用拷贝构造函数
a = test(b);//return时的临时image对象再用赋值操作符重载给a
image e = test(b);//return时的临时image对象无需再用拷贝构造函数初始e
}
