flower/include/pointer.hh

   1 /*
   2   pointer.hh -- declare P
   3
   4   source file of the Flower Library
   5
   6   (c) 1997 Han-Wen Nienhuys <hanwen@stack.nl>
   7 */
   8
   9
  10 #ifndef POINTER_HH
  11 #define POINTER_HH
  12
  13 /** P<T> is a handy template to use iso T*. It inits to 0, deletes on
  14   destruction, deep copies upon copying
  15
  16   It is probably not feasible to use P<T> as template argument, since
  17   a lot of auto conversion wouldn't work. new T would be called too
  18   much anyway.
  19
  20   Sorry for the silly naming */
  21 template <class T>
  22 class P {
  23     /**
  24       Set contents to a copy of #t_l#
  25      */
  26     void copy(T const*t_l);
  27     T* t_p;
  28
  29     /**
  30       junk contents and set to 0
  31      */
  32     void junk();
  33 public:
  34
  35     P(P const &src);
  36     /**
  37       Remove  the pointer, and return it.
  38      */
  39
  40     T *get_p() { T*p = t_p; t_p=0; return p; }
  41     /**
  42       return the pointer
  43      */
  44     T *get_l()  { return t_p; }
  45
  46     T const *get_C() const { return t_p; }
  47     /**
  48       copy the contents of pointer, and return it
  49      */
  50     T *copy_p() const;
  51     /**
  52       swallow new_p, and set contents t new_p
  53      */
  54     void set_p (T *new_p);
  55     /**
  56       junk contents, and  copy contents of t_l
  57      */
  58     void set_l (T const *t_C);
  59
  60     P &operator =(P const &);
  61     ~P();
  62     P() { t_p = 0; }
  63     //P(T *p) { t_p = p; }
  64
  65     T *operator ->() { return t_p; }
  66     operator T * () {  return t_p; }
  67     const T *operator ->() const { return t_p ; }
  68     T &operator *() { return *t_p; }
  69     T const  &operator *() const { return *t_p; }
  70     operator const T *() const { return t_p; }
  71 };
  72 #endif // POINTER_HH
  73
  74