Issue #10136 has been reported by Akira Tanaka.

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Bug #10136: printf("%.60f\n", 0.1r) shows 0.100000000000000005551115123125782702118158340454101562500000
https://bugs.ruby-lang.org/issues/10136

* Author: Akira Tanaka
* Status: Open
* Priority: Normal
* Assignee: 
* Category: 
* Target version: 
* ruby -v: ruby 2.2.0dev (2014-08-15 trunk 47187) [x86_64-linux]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN
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printf shows 0.1r (rational) not 0.1 as follows.

```
% ./ruby -ve 'printf "%.60f\n", 0.1r'
ruby 2.2.0dev (2014-08-15 trunk 47187) [x86_64-linux]
0.100000000000000005551115123125782702118158340454101562500000
```

It seems printf converts the rational argument to a float.

I expect 0.100000000000000000000000000000000000000000000000000000000000 instead of
0.100000000000000005551115123125782702118158340454101562500000.




-- 
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