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 static bool static_is_type_b(const char*s);\
  20 virtual bool is_type_b(const char *s)const { return static_is_type_b(s); } \
  21 virtual char const *name() const{ return static_name(); } \
  22 int a_stupid_nonexistent_function_to_allow_the_semicolon_come_out()
  23
  24 #define IMPLEMENT_STATIC_NAME(c)\
  25     char const *c::static_name() { return #c; }
  26
  27 #define VIRTUAL_COPY_CONS(T, R)\
  28   virtual R *clone() const { return  new T(*this); } \
  29   int  yet_another_stupid_function_to_allow_semicolon()
  30
  31 #define IMPLEMENT_IS_TYPE_B(D)                                                     \
  32     IMPLEMENT_STATIC_NAME(D)\
  33   bool D::static_is_type_b(const char *s)                                          \
  34 {                                                                                  \
  35     return s == static_name();                                                     \
  36 }
  37
  38 #define IMPLEMENT_IS_TYPE_B1(D,B)                                                  \
  39         IMPLEMENT_STATIC_NAME(D)\
  40   bool D::static_is_type_b(const char *s)                                                  \
  41 {                                                                                  \
  42     return s == static_name() || B::static_is_type_b(s);                                   \
  43 }
  44 #define IMPLEMENT_IS_TYPE_B2(D, BA, BB)                                                    \
  45         IMPLEMENT_STATIC_NAME(D)\
  46   bool D::static_is_type_b(const char *s)                                                  \
  47 {                                                                                  \
  48     return s == static_name() || BA::static_is_type_b(s) || BB::static_is_type_b(s); \
  49 }
  50
  51 #endif