关于C++的一些小知识点

void fun1(const char *p) {
  p[0] = 'a'; // x
  p = "hello";
}
void fun2(char * const p) {
  p[0] = 'a';
  p = "hello"; //x
}
void fun3(const char * const p) {
  p[0] = 'a'; //x
  p = "hello"; //x
}
//const只和*的前后位置有关，与类型无任何关系。

class Point
{
public:
  Point() : x(0), y(0) {}
  ~Point() {}
  Point(const Point&) {}
  Point& operator=(const Point&) {}
  Point(Point &&){}
  Point& operator=(Point &&) {}
  friend ostream & operator<<(ostream &out, Point &p);
private:
  int x, y;
};
ostream & operator<<(ostream &out, Point &p)
{
  out << p.x << " " << p.y;
  return out;
}
int main()
{
  Point p;
  std::cout << p << p;
}

int main()
{
  char *p = (char*)malloc(5);
  memcpy(p, "hello", 5);
  printf("%c %c\n", *p++, *p); //h e
  printf("%c %c\n", ++(*p), *p); //printf("%c %c\n", (*p)++, *p);
}