flower/include/virtual-methods.hh

   1 /*
   2   virtual-methods.hh -- declare
   3
   4   source file of the Flower Library
   5
   6   (c) 1997 Han-Wen Nienhuys <hanwen@stack.nl>
   7 */
   8
   9
  10 #ifndef VIRTUAL_METHODS_HH
  11 #define VIRTUAL_METHODS_HH
  12
  13 /** a macro to declare the classes name as a static and virtual function.
  14   The static_name() can *not* be inlined (this might have the effect that
  15   s->name() != S::static_name(). Overlapping strings need not be merged in C++
  16  */
  17 #define NAME_MEMBERS()  \
  18 static char const *static_name();\
  19 virtual bool is_type_b(const char *)const; \
  20 virtual char const *name() const{ return static_name(); } \
  21 int a_stupid_nonexistent_function_to_allow_the_semicolon_come_out()
  22
  23 #define IMPLEMENT_STATIC_NAME(c)\
  24     char const *c::static_name() { return #c; }
  25
  26 #define VIRTUAL_COPY_CONS(T, R)\
  27   virtual R *clone() const { return  new T(*this); } \
  28   int  yet_another_stupid_function_to_allow_semicolon()
  29
  30 #define IMPLEMENT_IS_TYPE_B(D)                                                     \
  31   bool D::is_type_b(const char *s)      const                                      \
  32 {                                                                                  \
  33     return s == static_name();                                                     \
  34 }
  35
  36 #define IMPLEMENT_IS_TYPE_B1(D,B)                                                  \
  37   bool D::is_type_b(const char *s)const                                            \
  38 {                                                                                  \
  39     return s == static_name() || B::is_type_b(s);                                  \
  40 }
  41 #define IMPLEMENT_IS_TYPE_B2(D, BA, BB)                                                    \
  42   bool D::is_type_b(const char *s)      const                                      \
  43 {                                                                                  \
  44     return s == static_name() || BA::is_type_b(s) || BB::is_type_b(s); \
  45 }
  46
  47 #endif