C++ 操作符重载
/* class 运算符重载 */
#include <iostream>
using namespace std;
class Box {
private:
int length;
public:
Box(int l=10);
int getLength();
void setLength(int x);
Box operator+(const Box &b);
bool operator<(const Box &b);
Box operator++ ();
Box operator++ (int);
/* output opt overload */
friend ostream &operator << (ostream &output, const Box &b) {
output << "Length:" << b.length << endl;
return output;
}
/* input opt overload */
friend istream &operator >> (istream &input, Box b) {
input >> b.length;
return input;
}
};
/* contructor */
Box::Box(int l) {
length = l;
}
/* operator+ */
Box Box::operator+(const Box &b) {
Box box;
box.length = this->length + b.length;
return box;
}
/* operation < */
bool Box::operator<(const Box &b) {
if (this->length < b.length) {
return true;
}
return false;
}
/* 重载前缀 */
Box Box::operator++ () {
++this->length;
return *this;
}
/* 重载后缀 */
Box Box::operator++ (int) {
Box temp = *this;
this->length++;
return temp;
}
int Box::getLength() {
return length;
}
void Box::setLength(int l) {
length = l;
}
int main() {
Box a; /* 10 default */
Box b(20);
Box c;
c.setLength(30); /* set to 30 */
Box t = a + b + c; /* should be 60 */
cout << "a + b :" << t.getLength() << endl;
cout << "a < b ? " << (c < b) << endl;
cout << a << endl;
cout << b << endl;
cout << "before++" << a++ << endl;
cout << "after" << a << endl;
cout << "++before" << ++a << endl;
cout << "after" << a << endl;
return 0;
}
