src/base/symbol/cl_sy_hashcode.cc

   1 // cln/symbol.hashcode().
   2
   3 // General includes.
   4 #include "base/cl_sysdep.h"
   5
   6 // Specification.
   7 #include "cln/symbol.h"
   8
   9
  10 // Implementation.
  11
  12 #include "base/cl_offsetof.h"
  13
  14 namespace cln {
  15
  16 #define declare_alignof(where,type)  \
  17   struct CONCAT(aligndummy,__LINE__) { char slot1; type slot2; }; \
  18   const unsigned long where = offsetof(CONCAT(aligndummy,__LINE__), slot2);
  19
  20 unsigned long hashcode (const cl_symbol& s)
  21 {
  22         // Strings don't move in memory, so we can just take the address.
  23         declare_alignof(string_alignment,cl_heap_string);
  24         return (unsigned long)(s.pointer)
  25                / (string_alignment & -string_alignment); // divide by power of 2
  26 }
  27
  28 }  // namespace cln