我想讓物件可以依照某個方式比大小,例如TButton以caption來比較:

bool operator<(TButton *b1,TButton *b2)
{
  return b1->Caption < b2->Caption;
}
bool operator==(TButton *b1,TButton *b2)
{
  return b1->Caption == b2->Caption;
}

但是complie錯誤: [C Error] Unit1.h(29): E2082 'operator <(TButton *,TButton *)' must be a member function or have a parameter of class type [C Error] Unit1.h(33): E2082 'operator ==(TButton *,TButton *)' must be a member function or have a parameter of class type 請問應該怎麼寫呢?

程式改成這樣試試看:

bool operator<(TButton& b1,TButton& b2)
{
  return b1.Caption < b2.Caption;
}
bool operator==(TButton& b1,TButton& b2)
{
  return b1.Caption == b2.Caption;
}

啊!可以了,改用*