Examples for C++ note (5)

Example 1

class foo {

  public: 
    foo(int i) { 
      cout << "Constructing." << endl;
      member = i;
    }
    foo(const FOO& other) { cout << "Copy constructing." << endl;
      member = other.member;
    }     
    ~foo() { 
      cout << "Destructing." << endl; 
    }
    int get() {
      return member;
    }

  private:
    int member;
};

void display(foo obj) {
  cout << obt.get() << endl;
}

foo get_foo() {
  int value;
  cout << "Input an integer: ";
  cin >> value;
  foo obj(value);
  return obj;
}

int main() {
  foo obj1(15);
  foo obj2 = obj1;
  display(obj2);
  obj2 = get_foo();
  display(obj2);

  return (0);
}

返回：隐式调用复制构造

Example 2

返回：复制策略：拷贝构造函数自定义