Issue #10612 has been reported by Robert A. Heiler.

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Bug #10612: Documentation: Document behaviour of Hash#invert
https://bugs.ruby-lang.org/issues/10612

* Author: Robert A. Heiler
* Status: Open
* Priority: Low
* Assignee: 
* Category: 
* Target version: 
* ruby -v: ruby 2.1.5p273 (2014-11-13 revision 48405) [i686-linux]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN
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Currently a hash loses data if an .invert is done:

    {"hey"=>3, "there"=>3, "yippie"=>3, "ack"=>2, "ackack"=>9, "thore"=>3, "yippa"=>9}.invert

Result:

    # {3=>"thore", 2=>"ack", 9=>"yippa"}

In the example, this is shown, but it is not documented at:

  http://www.ruby-doc.org/core-2.1.5/Hash.html#method-i-invert

As the example already shows it, my suggestion is to extend the documentation
with a sentence such as this:

"If a key with the same name already exists in the Hash then the
last one defined will be used, the earlier key will be discarded."

Or something similar to this.



-- 
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