From: nobu@...
Date: 2016-05-03T05:28:20+00:00
Subject: [ruby-dev:49607] [Ruby trunk Bug#12339][Assigned] result of	123456789 ** -2 in doc

Issue #12339 has been updated by Nobuyoshi Nakada.

Status changed from Open to Assigned
Assignee set to Kazuhiro NISHIYAMA
Backport changed from 2.1: UNKNOWN, 2.2: UNKNOWN, 2.3: UNKNOWN to 2.1: REQUIRED, 2.2: REQUIRED, 2.3: REQUIRED

1.9でRationalが組み込みになって動作が変わったはずです。

----------------------------------------
Bug #12339: result of 123456789 ** -2 in doc
https://bugs.ruby-lang.org/issues/12339#change-58445

* Author: Kazuhiro NISHIYAMA
* Status: Assigned
* Priority: Normal
* Assignee: Kazuhiro NISHIYAMA
* ruby -v: ruby 2.4.0dev (2016-05-02 trunk 54882) [x86_64-darwin14]
* Backport: 2.1: REQUIRED, 2.2: REQUIRED, 2.3: REQUIRED
----------------------------------------
https://github.com/ruby/ruby/blob/c353ec0c9e8e941f49910a51f7dc10cf3d3cdd17/numeric.c#L3647
の `Integer#**` の rdoc で

```
 *    123456789 ** -2     #=> 6.5610001194102e-17
```

となっていますが、実際に試してみると `(1/15241578750190521)` になります。
どちらが正しいのでしょうか?

```
%  ruby -ve 'p 123456789 ** -2'
ruby 2.4.0dev (2016-05-02 trunk 54882) [x86_64-darwin14]
(1/15241578750190521)
```



-- 
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