text: #include <limits.h>
  #include <mruby.h>
  
  static inline mrb_int
  to_int(mrb_state *mrb, mrb_value x)
  {
    x = mrb_to_int(mrb, x);
    return mrb_fixnum(x);
  }
  
  /*
   *  Document-method: Integer#chr
   *  call-seq:
   *     int.chr  ->  string
   *
   *  Returns a string containing the character represented by the +int+'s value
   *  according to +encoding+.
   *
   *     65.chr    #=> "A"
   *     230.chr   #=> "\xE6"
   */
  static mrb_value
  mrb_int_chr(mrb_state *mrb, mrb_value x)
  {
    mrb_int chr;
    char c;
  
    chr = to_int(mrb, x);
    if (chr >= (1 << CHAR_BIT)) {
      mrb_raisef(mrb, E_RANGE_ERROR, "%S out of char range", x);
    }
    c = (char)chr;
  
    return mrb_str_new(mrb, &c, 1);
  }
  
  /*
   *  call-seq:
   *     int.allbits?(mask)  ->  true or false
   *
   *  Returns +true+ if all bits of <code>+int+ & +mask+</code> are 1.
   */
  static mrb_value
  mrb_int_allbits(mrb_state *mrb, mrb_value self)
  {
    mrb_int n, m;
  
    mrb_get_args(mrb, "i", &m);
    n = to_int(mrb, self);
    return mrb_bool_value((n & m) == m);
  }
  
  /*
   *  call-seq:
   *     int.anybits?(mask)  ->  true or false
   *
   *  Returns +true+ if any bits of <code>+int+ & +mask+</code> are 1.
   */
  static mrb_value
  mrb_int_anybits(mrb_state *mrb, mrb_value self)
  {
    mrb_int n, m;
  
    mrb_get_args(mrb, "i", &m);
    n = to_int(mrb, self);
    return mrb_bool_value((n & m) != 0);
  }
  
  /*
   *  call-seq:
   *     int.nobits?(mask)  ->  true or false
   *
   *  Returns +true+ if no bits of <code>+int+ & +mask+</code> are 1.
   */
  static mrb_value
  mrb_int_nobits(mrb_state *mrb, mrb_value self)
  {
    mrb_int n, m;
  
    mrb_get_args(mrb, "i", &m);
    n = to_int(mrb, self);
    return mrb_bool_value((n & m) == 0);
  }
  
  void
  mrb_mruby_numeric_ext_gem_init(mrb_state* mrb)
  {
    struct RClass *i = mrb_module_get(mrb, "Integral");
  
    mrb_define_method(mrb, i, "chr", mrb_int_chr, MRB_ARGS_NONE());
    mrb_define_method(mrb, i, "allbits?", mrb_int_allbits, MRB_ARGS_REQ(1));
    mrb_define_method(mrb, i, "anybits?", mrb_int_anybits, MRB_ARGS_REQ(1));
    mrb_define_method(mrb, i, "nobits?", mrb_int_nobits, MRB_ARGS_REQ(1));
  }
  
  void
  mrb_mruby_numeric_ext_gem_final(mrb_state* mrb)
  {
  }
  