# \[Bug:1.8\] compatibility issue of BigDecimal#\*\* and #power

**URL:** <https://www.ruby-forum.com/t/bug-1-8-compatibility-issue-of-bigdecimal-and-power/182316>\
**Category:** Development\
**Created:** [January 26, 2010, 3:02pm UTC](https://www.ruby-forum.com/t/bug-1-8-compatibility-issue-of-bigdecimal-and-power/182316 "2010-01-26T15:02:38Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [January 26, 2010, 3:02pm UTC](https://www.ruby-forum.com/t/bug-1-8-compatibility-issue-of-bigdecimal-and-power/182316/1 "2010-01-26T15:02:38Z")

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e$B$^$D$b$H$5$s$+KNIt$5$se(B  
e$B1sF#$G$9!#e(B

BigDecimal#\*\* e$B$He(B #power e$B$N;EMMJQ99$,e(B trunk e$B$+$ie(B  
ruby\_1\_8 e$B$K%P%C%/%]!\<%He(B  
e$B$5$l$F$$$^$9$,!"$3$l$Oe(B 1.8.7 e$B0JA0$HHf$Y$FHs8\_49$JJQ99$G$9!#e(B

$ ruby -v -rbigdecimal -e ‘p BigDecimal(“Infinity”) \*\* -5’  
ruby 1.8.7 (2008-08-11 patchlevel 72) [i486-linux]  
#BigDecimal:b7c45204,‘NaN’,4(8)

$ ruby18 -v -rbigdecimal -e ‘p BigDecimal(“Infinity”) \*\* -5’  
ruby 1.8.8dev (2010-01-26 revision 26430) [i686-linux]  
#BigDecimal:b7d18c80,‘0.0’,4(8)

$ ruby19 -v -rbigdecimal -e ‘p BigDecimal(“Infinity”) \*\* -5’  
ruby 1.9.2dev (2010-01-26 trunk 26420) [i686-linux]  
#BigDecimal:824cf7c,‘0.0’,4(8)

e$BJQ99FbMF$Oe(B [ruby-dev:36159] e$B$Ne(B 1 e$B$D$a$N!"!Ve(BInfinity  
e$B$NN\_\>h$re(B NaN e$B$G$J$/e(B  
0 e$B$de(B Inf e$B$de(B -Inf e$B$K$9$k!W$H$$$&$b$N$G$9!#e(B

1.8.8 e$B$KHs8\_49$JJQ99$rF~$l$k$N$O$h$/$J$$$H;W$&$N$G$9$,!"e(B

- 1.8.7 e$B0JA0$N%P%0$@$C$?e(B (1.8.6/1.8.7  
e$B$K$b%P%C%/%]!\<%H$9$Y$-e(B)
- 1.9 e$B$+$i$N;EMMJQ99e(B (ruby\_1\_8 e$B$X$N%P%C%/%]!\<%H$Oe(B revert  
e$B$9$Y$-e(B)

e$B$N$I$A$i$H9M$($k$Y$-$G$7$g$&$+!#e(Brubyspec  
e$B$X$N=$@50MMj$K1F6A$7$^$9!#e(B

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<div class="post-metadata">

**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [January 27, 2010, 5:47am UTC](https://www.ruby-forum.com/t/bug-1-8-compatibility-issue-of-bigdecimal-and-power/182316/2 "2010-01-27T05:47:21Z")

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Yusuke ENDOH e$B$5$s$O=q$-$^$7$?e(B:

> 1.8.8 e$B$KHs8\_49$JJQ99$rF~$l$k$N$O$h$/$J$$$H;W$&$N$G$9$,!"e(B

e$B$d$`$r$($J$$;~$O$d$`$r$($J$$$H;W$$$^$9$,!"$3$N%1!\<%9$O$I$&$J$N$+$Je(B

> - 1.8.7 e$B0JA0$N%P%0$@$C$?e(B (1.8.6/1.8.7 e$B$K$b%P%C%/%]!\<%H$9$Y$-e(B)
> - 1.9 e$B$+$i$N;EMMJQ99e(B (ruby\_1\_8 e$B$X$N%P%C%/%]!\<%H$Oe(B revert e$B$9$Y$-e(B)
> 
> e$B$N$I$A$i$H9M$($k$Y$-$G$7$g$&$+!#e(Brubyspec e$B$X$N=$@50MMj$K1F6A$7$^$9!#e(B

e$B%P%0$@$C$?$H$$$&H=CG$J$ie(B1.8.7e$B$K$b%P%C%/%]!\<%H$7$^$9!#8D?ME\*$K$O$I$C$A$G$b$$$$5$e(B  
e$B$,$7$^$9!#e(B

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<div class="post-metadata">

**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [January 27, 2010, 8:11am UTC](https://www.ruby-forum.com/t/bug-1-8-compatibility-issue-of-bigdecimal-and-power/182316/3 "2010-01-27T08:11:53Z")

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e$B:XF#$H?=$7$^$9!#e(B

On Tue, 26 Jan 2010 23:02:03 +0900  
Yusuke ENDOH [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> - 1.8.7 e$B0JA0$N%P%0$@$C$?e(B (1.8.6/1.8.7 e$B$K$b%P%C%/%]!\<%H$9$Y$-e(B)

e$BEvA3$3$C$A$@$H;W$$$^$9!#e(B

1 / Infinity (=\> 0) e$B$He(B Infinity \*\* -1 (=\> NaN?)  
e$B$,0[$J$k$N$O$\*$+$7$$$G$9!#e(B

e$B$^$?\<+J,$O?t3X$K$“$^$j\>$7$/$”$j$^$;$s$,!“$b$7e(B  
1  
— e$B”\*e(B 0 (n e$B"_e(B e$B!ge(B)  
n  
e$B$,@.$jN)$?$J$$$J$i$P!“$3$N9q$N9b9;@8$,=,$&?t3X$9$iH]Dj$9$k7O$re(BRubye$B$,:N$C$F$$$k$3$H$Ke(B  
e$B$J$k$G$7$g$&!#$G!”\<+J,$O$=$&$$$&7O$,0lHLE_$G$J$$$H?.$8$F$$$^$9!#e(B

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<div class="post-metadata">

**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [January 27, 2010, 10:20am UTC](https://www.ruby-forum.com/t/bug-1-8-compatibility-issue-of-bigdecimal-and-power/182316/4 "2010-01-27T10:20:39Z")

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e$B$^$D$b$He(B e$B$f$-$R$m$G$9e(B

In message “Re: [ruby-dev:40172] Re: [Bug:1.8] compatibility issue of  
BigDecimal#\*\* and #power”  
on Wed, 27 Jan 2010 16:09:18 +0900, Tadashi S.  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

|\> - 1.8.7 e$B0JA0$N%P%0$@$C$?e(B (1.8.6/1.8.7 e$B$K$b%P%C%/%]!\<%H$9$Y$-e(B)  
|  
|e$BEvA3$3$C$A$@$H;W$$$^$9!#e(B  
|  
|1 / Infinity (=\> 0) e$B$He(B Infinity \*\* -1 (=\> NaN?) e$B$,0[$J$k$N$O$\*$+$7$$$G$9!#e(B

e$B;d$b%P%0$@$H;W$$$^$9$,!"\<B:]$Ke(BDecimale$B$r;H$&?M$,!“85$NJ}$,$&e(B  
e$B$l$7$$$H$$$&$N$G$”$l$Pe(B(1.9e$B$b4^$a$Fe(B)e$B!"La$7$F$b9=$$$^$;$s!#e(B

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<div class="post-metadata">

**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [January 27, 2010, 10:55am UTC](https://www.ruby-forum.com/t/bug-1-8-compatibility-issue-of-bigdecimal-and-power/182316/5 "2010-01-27T10:55:46Z")

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e$BKNIt$G$9!#e(B

Yukihiro M. e$B$5$s$O=q$-$^$7$?e(B:

> |1 / Infinity (=\> 0) e$B$He(B Infinity \*\* -1 (=\> NaN?) e$B$,0[$J$k$N$O$\*$+$7$$$G$9!#e(B
> 
> e$B;d$b%P%0$@$H;W$$$^$9$,!"\<B:]$Ke(BDecimale$B$r;H$&?M$,!“85$NJ}$,$&e(B  
> e$B$l$7$$$H$$$&$N$G$”$l$Pe(B(1.9e$B$b4^$a$Fe(B)e$B!"La$7$F$b9=$$$^$;$s!#e(B

e$B$I$&$d$i%P%0$H$$$&%3%s%;%s%5%9$,:n$i$l$D$D$"$j$=$&$G$7$g$&$+!#$=$l$O$=$l$G;d$Oe(B  
e$B:$$j$^$;$s!#e(B

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<div class="post-metadata">

**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [January 27, 2010, 10:08am UTC](https://www.ruby-forum.com/t/bug-1-8-compatibility-issue-of-bigdecimal-and-power/182316/6 "2010-01-27T10:08:22Z")

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e$BKNIt$G$9e(B

Tadashi S. e$B$5$s$O=q$-$^$7$?e(B:

> e$B$,@.$jN)$?$J$$$J$i$P!"$3$N9q$N9b9;@8$,=,$&?t3X$9$iH]Dj$9$k7O$re(B

e$B$1$Ie(B 3/2 # =\> 1 e$B$J7O$r:NMQ$7$F$k$7$J$"!#e(B

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<div class="post-metadata">

**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [January 28, 2010, 12:27pm UTC](https://www.ruby-forum.com/t/bug-1-8-compatibility-issue-of-bigdecimal-and-power/182316/7 "2010-01-28T12:27:03Z")

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e$B1sF#$G$9!#e(B

2010e$BG/e(B1e$B7ne(B27e$BF|e(B18:51 Urabe S.  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):

> Yukihiro M. e$B$5$s$O=q$-$^$7$?e(B:
> 
> > |1 / Infinity (=\> 0) e$B$He(B Infinity \*\* -1 (=\> NaN?) e$B$,0[$J$k$N$O$\*$+$7$$$G$9!#e(B
> > 
> > e$B;d$b%P%0$@$H;W$$$^$9$,!"\<B:]$Ke(BDecimale$B$r;H$&?M$,!“85$NJ}$,$&e(B  
> > e$B$l$7$$$H$$$&$N$G$”$l$Pe(B(1.9e$B$b4^$a$Fe(B)e$B!"La$7$F$b9=$$$^$;$s!#e(B
> 
> e$B$I$&$d$i%P%0$H$$$&%3%s%;%s%5%9$,:n$i$l$D$D$"$j$=$&$G$7$g$&$+!#$=$l$O$=$l$G;d$Oe(B  
> e$B:$$j$^$;$s!#e(B

e$B$=$l$G$O!"e(B1.8.7  
e$B$K%P%C%/%]!\<%H$9$k$H$$$&7kO@$G$$$$$G$7$g$&$+!#e(B

e$B$3$l$,%P%C%/%]!\<%H$5$l$k$J$i!"e(B[ruby-dev:36159] e$B$Ne(B 2)  
e$B$O$5$i$K%P%0e(B  
e$B$C$]$$$N$G%P%C%/%]!\<%H$7$FM\_$7$$$G$9!#e(B