C++内联函数

class Screen
{
public:
    Screen(void);
    ~Screen(void);

    typedef string::size_type pos;

    Screen(pos ht,pos wd,char c):height(ht),width(wd),contents(ht*wd,c){}

    char get() const{return contents[cursor];}
    inline char get(pos ht,pos wd)const;
    Screen &move(pos r,pos c);
    //using pos = string::size_type;
private:
    pos cursor;
    pos width;
    pos height;
    string contents;

};
inline Screen& Screen::move(pos r,pos c)
{
    pos row = r*width;
    cursor = row +c;
    return *this;
}

char Screen::get(pos r,pos c)const
{
    pos row = r*width;
    return contents[row+c];
}