# Bug: power! does not work then works in irb

**URL:** <https://www.ruby-forum.com/t/bug-power-does-not-work-then-works-in-irb/57306>\
**Category:** Ruby\
**Created:** [April 9, 2006, 3:22pm UTC](https://www.ruby-forum.com/t/bug-power-does-not-work-then-works-in-irb/57306 "2006-04-09T15:22:20Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![solsTiCe\_dSHiver](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/8e8cbc/32.png) [@solsTiCe\_dSHiver](https://www.ruby-forum.com/u/solsTiCe_dSHiver)\
**Post date:** [April 9, 2006, 3:22pm UTC](https://www.ruby-forum.com/t/bug-power-does-not-work-then-works-in-irb/57306/1 "2006-04-09T15:22:20Z")

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hi.

here is a session in irb:  
irb(main):001:0\> 10.power!(200)  
NoMethodError: undefined method `power!’ for 10:Fixnum  
from (irb):1  
irb(main):002:0\> help Fixnum  
=\> nil  
irb(main):003:0\> 10.power!(200)  
=\>  
100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000  
irb(main):004:0\> quit

so a call to help Fixnum makes the power! method to be available ?

i use slackare 10.2 with a self-made package of ruby 1.8.4 compiled with  
CFLAGS=“-O2 -march=$arch -mcpu=i686”   
CXXFLAGS=“-O2 -march=$arch -mcpu=i686”  
./configure --prefix=/usr --enable-shared  
make  
make install DESTDIR=$pkg  
make install-doc DESTDIR=$pkg

on an Athlon XP 1800+

# note:

not all people on #ruby-lang on [irc.freenode.net](http://irc.freenode.net) got that error

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<div class="post-metadata">

**Author:** ![solsTiCe\_dSHiver](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/8e8cbc/32.png) [@solsTiCe\_dSHiver](https://www.ruby-forum.com/u/solsTiCe_dSHiver)\
**Post date:** [April 9, 2006, 3:28pm UTC](https://www.ruby-forum.com/t/bug-power-does-not-work-then-works-in-irb/57306/2 "2006-04-09T15:28:33Z")

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I just tried this on Osx and got the same result!

Keith

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**Author:** ![solsTiCe\_dSHiver](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/8e8cbc/32.png) [@solsTiCe\_dSHiver](https://www.ruby-forum.com/u/solsTiCe_dSHiver)\
**Post date:** [April 9, 2006, 3:31pm UTC](https://www.ruby-forum.com/t/bug-power-does-not-work-then-works-in-irb/57306/3 "2006-04-09T15:31:42Z")

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Hi,

You probably saw my reply on IRC but for others…

2006/4/9, solsTiCe d’Hiver [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):

> hi.
> 
> here is a session in irb:  
> irb(main):001:0\> 10.power!(200)  
> NoMethodError: undefined method `power!’ for 10:Fixnum  
> from (irb):1  
> irb(main):002:0\> help Fixnum  
> =\> nil

This is actually a valid call. To see what help is from try:

method :help

You might get something like:

#\<Method: Object(IRB::ExtendCommandBundle)#help\>

The part in () tells us that it is from IRB… a quick check shows  
that a trail is started  
that eventually leads to:

require ‘mathn’

That file in turn, does something like:

alias power! \*\*

The reason not all people got the error is because some were probably  
loading other code at startup or before testing. Rubygems is an  
example of this.

Moral of the story is to be away of what your ruby environment  
automatically brings in.

Brian.

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<div class="post-metadata">

**Author:** ![solsTiCe\_dSHiver](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/8e8cbc/32.png) [@solsTiCe\_dSHiver](https://www.ruby-forum.com/u/solsTiCe_dSHiver)\
**Post date:** [April 9, 2006, 3:44pm UTC](https://www.ruby-forum.com/t/bug-power-does-not-work-then-works-in-irb/57306/4 "2006-04-09T15:44:01Z")

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Hi,

At Sun, 9 Apr 2006 22:19:23 +0900,  
solsTiCe d’Hiver wrote in [ruby-talk:188278]:

> here is a session in irb:  
> irb(main):001:0\> 10.power!(200)  
> NoMethodError: undefined method `power!’ for 10:Fixnum  
> from (irb):1

power! is for internal use only. Do not use.

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<div class="post-metadata">

**Author:** ![solsTiCe\_dSHiver](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/8e8cbc/32.png) [@solsTiCe\_dSHiver](https://www.ruby-forum.com/u/solsTiCe_dSHiver)\
**Post date:** [April 9, 2006, 6:45pm UTC](https://www.ruby-forum.com/t/bug-power-does-not-work-then-works-in-irb/57306/5 "2006-04-09T18:45:24Z")

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----- Original Message -----  
From: “solsTiCe d’Hiver” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
To: “ruby-talk ML” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
Sent: Sunday, April 09, 2006 9:19 AM  
Subject: [ruby 1.8.4] bug: power! does not work then works in irb

> 100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000  
> irb(main):004:0\> quit
> 
> so a call to help Fixnum makes the power! method to be available ?

I get the same behavior … using ruby on Windows XP … the binary  
distribution