定义一个计数器Counter，包含私有变量，重载运算符“+，实现对象的相加c++语言

class Counter {
private:
int count;
public:
Counter() : count(0) {}
Counter(int c) : count(c) {}
int getCount() const { return count; }
void setCount(int c) { count = c; }
Counter operator+(const Counter& c) const {
return Counter(count + c.count);
}
};