dev80

#include <iostream>

#include <cstring>

using namespace std;

class String {

char buf[1000];

public:

String(const char* sz) 

{

strcpy(buf, sz);

}

~String() {}

operator const char* () const 

{

return buf;

}

};

int main()

{

String s("Hello");

const char* sz = s;

cout << sz << endl;

}

operator const char* () const
{
 return buf;
}

형변환 연산자 오버로딩

return buf; 이므로 String 클래스 안에 있는 맴버 buf를 return

형변환 연산자 오버로딩은 

operator 타입명 () const

으로 원형을 정의한다.

#include <iostream>

using namespace std;

class Point {

int x;

int y;

public:

Point(int _x = 0, int _y = 0) :x(_x), y(_y) {}

void Print() const { cout << x << ", " << endl; }

};

class PointPtr

{

Point *ptr;

public:

PointPtr(Point *p) :ptr(p) {}

~PointPtr() { delete ptr; }

Point* operator->() const

{

return ptr;

}

Point& operator*() const

{

return *ptr;

}

};

int main()

{

Point* p1 = new Point(2, 3);

PointPtr p2 = new Point(5, 5);

p1->Print();

p2->Print();

return 0;

}

p1은 일반 포인터, p2가 스마트 포인터

#include <iostream>

using namespace std;

class Point {

int x, y;

public:

Point(int _x = 0, int _y = 0) :x(_x), y(_y) {}

void Print() const {

cout << x << ", " << y << endl;

}

const Point operator+(const Point &arg) const

{

Point pt;

pt.x = this->x + arg.x;

pt.y = this->y + arg.y;

return pt;

}

const Point& operator++()

{

++x;

++y;

return *this;

}

const Point operator++(int)

{

Point pt(x, y);

++x;

++y;

return pt;

}

};

int main()

{

Point pt1(2, 3);

Point pt2(3, 5);

++pt2;

Point pt3;

pt3 = pt1 + pt2;

pt3.Print();

pt2.Print();

return 0;

}