Visual Studio 2019复制粘贴的代码划红线，但是照着重打一遍就能跑了？这是为什么？

pch.h文件：

class Clock
{
private:
    int hour;
    int minute;
    int second;
public:
    void SetTime(int h, int m, int s);
    Clock(Clock& c);
    Clock(int h, int m, int s);
    ~Clock(void);
    void ShowTime();
};

pch.cpp文件

#include "pch.h"
#include<iostream>
using namespace std;
Clock::Clock(Clock& c) 
{
    hour = c.hour;
    minute = c.minute;
    second = c.second;
    cout << "The new clock: ";
    ShowTime();
    cout << " is copy constructed" << endl;
}
Clock::Clock(int h, int m, int s) 
{
    hour = h;
    minute = m;
    second = s;
    cout << "The new clock: ";
    ShowTime();
    cout << " is constructed!" << endl;
}
Clock::~Clock(void) 
{
    cout << "The clock: ";
    ShowTime();
    cout << " is destructed" << endl;
}
void Clock::SetTime(int h, int m, int s)
{
    hour = h;
    minute = m;
    second = s;
}
void Clock::ShowTime() 
{
    cout << hour << ":" << minute << ":" << second;
}

clock.cpp文件：

#include "pch.h"
#include <iostream>
using namespace std;
Clock Ring（Clock c)
{
    c.ShoweTime();
    cout << "Clock is ringing!" << endl;
    return c;
}
//Clock Ring(Clock c)
//{
//  c.ShowTime();
//  cout << "Clock is ringing!" << endl;
//  return c;
//}
void main()
{
    Clock c1(11, 20, 30);
    c1.ShowTime();
    cout << endl;
    Ring(c1);
    system("pause");

}