text: /*
  ** mruby/boxing_word.h - word boxing mrb_value definition
  **
  ** See Copyright Notice in mruby.h
  */
  
  #ifndef MRUBY_BOXING_WORD_H
  #define MRUBY_BOXING_WORD_H
  
  #if defined(MRB_INT16)
  # error MRB_INT16 is too small for MRB_WORD_BOXING.
  #endif
  
  #if defined(MRB_INT64) && !defined(MRB_64BIT)
  #error MRB_INT64 cannot be used with MRB_WORD_BOXING in 32-bit mode.
  #endif
  
  struct RFloat {
    MRB_OBJECT_HEADER;
    mrb_float f;
  };
  
  struct RCptr {
    MRB_OBJECT_HEADER;
    void *p;
  };
  
  #define MRB_FIXNUM_SHIFT 1
  #define MRB_TT_HAS_BASIC MRB_TT_FLOAT
  
  enum mrb_special_consts {
    MRB_Qnil    = 0,
    MRB_Qfalse  = 2,
    MRB_Qtrue   = 4,
    MRB_Qundef  = 6,
  };
  
  #define MRB_FIXNUM_FLAG   0x01
  #define MRB_SYMBOL_FLAG   0x0e
  #define MRB_SPECIAL_SHIFT 8
  
  typedef union mrb_value {
    union {
      void *p;
      struct {
        unsigned int i_flag : MRB_FIXNUM_SHIFT;
        mrb_int i : (MRB_INT_BIT - MRB_FIXNUM_SHIFT);
      };
      struct {
        unsigned int sym_flag : MRB_SPECIAL_SHIFT;
        mrb_sym sym : (sizeof(mrb_sym) * CHAR_BIT);
      };
      struct RBasic *bp;
      struct RFloat *fp;
      struct RCptr *vp;
    } value;
    unsigned long w;
  } mrb_value;
  
  MRB_API mrb_value mrb_word_boxing_cptr_value(struct mrb_state*, void*);
  MRB_API mrb_value mrb_word_boxing_float_value(struct mrb_state*, mrb_float);
  MRB_API mrb_value mrb_word_boxing_float_pool(struct mrb_state*, mrb_float);
  
  #define mrb_float_pool(mrb,f) mrb_word_boxing_float_pool(mrb,f)
  
  #define mrb_ptr(o)     (o).value.p
  #define mrb_cptr(o)    (o).value.vp->p
  #define mrb_float(o)   (o).value.fp->f
  #define mrb_fixnum(o)  ((mrb_int)(o).value.i)
  #define mrb_symbol(o)  (o).value.sym
  
  static inline enum mrb_vtype
  mrb_type(mrb_value o)
  {
    switch (o.w) {
    case MRB_Qfalse:
    case MRB_Qnil:
      return MRB_TT_FALSE;
    case MRB_Qtrue:
      return MRB_TT_TRUE;
    case MRB_Qundef:
      return MRB_TT_UNDEF;
    }
    if (o.value.i_flag == MRB_FIXNUM_FLAG) {
      return MRB_TT_FIXNUM;
    }
    if (o.value.sym_flag == MRB_SYMBOL_FLAG) {
      return MRB_TT_SYMBOL;
    }
    return o.value.bp->tt;
  }
  
  #define mrb_bool(o)    ((o).w != MRB_Qnil && (o).w != MRB_Qfalse)
  #define mrb_fixnum_p(o) ((o).value.i_flag == MRB_FIXNUM_FLAG)
  #define mrb_undef_p(o) ((o).w == MRB_Qundef)
  #define mrb_nil_p(o)  ((o).w == MRB_Qnil)
  
  #define BOXWORD_SET_VALUE(o, ttt, attr, v) do { \
    switch (ttt) {\
    case MRB_TT_FALSE:  (o).w = (v) ? MRB_Qfalse : MRB_Qnil; break;\
    case MRB_TT_TRUE:   (o).w = MRB_Qtrue; break;\
    case MRB_TT_UNDEF:  (o).w = MRB_Qundef; break;\
    case MRB_TT_FIXNUM: (o).w = 0;(o).value.i_flag = MRB_FIXNUM_FLAG; (o).attr = (v); break;\
    case MRB_TT_SYMBOL: (o).w = 0;(o).value.sym_flag = MRB_SYMBOL_FLAG; (o).attr = (v); break;\
    default:            (o).w = 0; (o).attr = (v); if ((o).value.bp) (o).value.bp->tt = ttt; break;\
    }\
  } while (0)
  
  #define SET_FLOAT_VALUE(mrb,r,v) r = mrb_word_boxing_float_value(mrb, v)
  #define SET_CPTR_VALUE(mrb,r,v) r = mrb_word_boxing_cptr_value(mrb, v)
  #define SET_NIL_VALUE(r) BOXWORD_SET_VALUE(r, MRB_TT_FALSE, value.i, 0)
  #define SET_FALSE_VALUE(r) BOXWORD_SET_VALUE(r, MRB_TT_FALSE, value.i, 1)
  #define SET_TRUE_VALUE(r) BOXWORD_SET_VALUE(r, MRB_TT_TRUE, value.i, 1)
  #define SET_BOOL_VALUE(r,b) BOXWORD_SET_VALUE(r, b ? MRB_TT_TRUE : MRB_TT_FALSE, value.i, 1)
  #define SET_INT_VALUE(r,n) BOXWORD_SET_VALUE(r, MRB_TT_FIXNUM, value.i, (n))
  #define SET_SYM_VALUE(r,v) BOXWORD_SET_VALUE(r, MRB_TT_SYMBOL, value.sym, (v))
  #define SET_OBJ_VALUE(r,v) BOXWORD_SET_VALUE(r, (((struct RObject*)(v))->tt), value.p, (v))
  #define SET_UNDEF_VALUE(r) BOXWORD_SET_VALUE(r, MRB_TT_UNDEF, value.i, 0)
  
  #endif  /* MRUBY_BOXING_WORD_H */
  