From: Tanaka Akira <akr@...17n.org>
Date: 2001-12-15T22:52:34+09:00
Subject: [ruby-dev:15460] Re: Time#utcoff

In article <200112150507.fBF571I17696@sharui.nakada.kanuma.tochigi.jp>,
  nobu.nakada@nifty.ne.jp writes:

> At Sat, 15 Dec 2001 13:44:33 +0900,
> Tanaka Akira <akr@m17n.org> wrote:
> > $B$?$@!"(B((time_t)-1L << 31) $B$G$b<BMQ>eLdBj$J$$$H$O;W$&$s$G$9$,!"(B
> > Standard C $B$rD4$Y$F=EH"$N6y$r$D$D$/$N$,LLGr$$$N$G!"$D$$;XE&$7$F$7$^$&(B
> > $B$H!"(Bsignd long $B$G$"$k$H$3$m$N(B -1L $B$r(B time_t $B$K%-%c%9%H$9$k$H$-$K(B
> > time_t $B$,(B unsigned $B$G$"$k$H(B implementation defined $B$J?6Iq$$$K$J$j$^$9!#(B

$B$3$l$O$+$J$jIT@53N$G$7$?!#(B

  time_t $B$,Id9f$J$7$G(B long $B$h$j$b%S%C%H?t$,>/$J$$$H(B implementation
  defined $B$K$J$k!#(B

$B$D$^$j!"(Btime_t $B$,(B signed long $B$+(B unsigned long $B$G$"$l$P%S%C%H?t$,F1$8(B
$B$J$N$G(B implementation defined $B$K$O$J$j$^$;$s$N$GId9f$J$7$J$i;v<B>eLdBj(B
$B$J$$$h$&$G$9!#(B

$B$?$@!"$5$i$KD4$Y$?$H$3$m!"(Btime_t $B$O(B arithmetic type $B$N$I$l$+$G$"$j!"Ib(B
$BF0>.?tE@$N2DG=@-$,$"$k$H$$$&$3$H$K5$$,$D$$$F$7$^$$$^$7$?!#$H$9$k$H%7%U(B
$B%H$,;H$($J$$$3$H$K$J$j$^$9!#(B

> $B0l1~$=$l$b9M$($?$s$G$9$,!"$d$C$Q$j8^==JbI4Jb$+$J$H!#(B

$B8=<B$r9M$($k$H$I$l$G$bF1$8$J$N$O$?$7$+$G$9!#(B
# $B$@$l$+0c$$$,=P$k<BNc$rCN$C$F$$$?$i65$($F2<$5$$!#(B

> $B$&!<$s!"5,3J=q$O;}$C$F$J$$$s$G$9$,!"(B(-(time_t)1 << 31)$B$C$F$N$b(B
> $B%@%a$G$7$?$C$1!#(Bunsinged$B$KBP$9$k(B-$B<+BN$,%@%a$+$J!#(B

$BHO0O30$K=P$A$c$&1i;;$O(B overflow $B$H$$$&$3$H$K$J$C$F$3$l$,(B undefined $B$J(B
$B$s$G$9$h$M$'!#(B

> $B$"$k$$$O!"(Bundefined$B$G$J$$$N$J$i$3$s$J$N$H$+!#(B
> 
>   if ((time_t)-1L >= (time_t)0) return 1;

$B$*$)!"$3$l$O$J$+$J$+!#(Btime_t $B$GIi$NCM$,I=8=ITG=$J$iEvA3(B
localtime/gmtime $B$G$b07$($J$$$O$:$@$+$i$3$l$G$$$$$o$1$G$9$M!#(B

$B$?$@!"(B-1L $B$h$j(B -1 $B$N$[$&$,$$$$$+$J!#(BL $B$,$D$$$F$$$k$F(B time_t $B$,(B long $B$h(B
$B$j$bC;$$$H(B implementation defined $B$K$J$C$A$c$&$N$G!#(B

In article <20011215145307.C780.ZN@mbf.nifty.com>,
  Kazuhiro NISHIYAMA <zn@mbf.nifty.com> writes:

> -2147483647-1$B$8$c%@%a$J$s$G$7$g$&$+!)(B

int $B$,(B 32bit $B$N(B 1$B$NJd?t$JI=8=$G(B time_t $B$,(B long $B$G(B 64bit $B$H$$$&$H$-$K<:(B
$BGT$9$k!"$+$J(B?

$B7k6I!"(B

* $B%S%C%H1i;;$G%G!<%?$r:n$k$HIi$N?t$N%U%)!<%^%C%H$K0MB8$9$k!#$?$V$s!#(B

* $B2C8:;;$G%G!<%?$r:n$k$H(B overflow $B$G(B undefined $B$K$J$k!#(B

$B$N$G!"L5M}$J$s$8$c$J$$$+$J$!!"$H$$$&5$$,$7$^$9!#(B
-- 
[$BEDCf(B $BE/(B][$B$?$J$+(B $B$"$-$i(B][Tanaka Akira]
$B!V$U$($m(B! $B$o$+$a$A$c$s:n@o$G$9$(C"=$B!W(B(Little Worker, $B7KM7@84](B)