Documentation for Pair class is much more confusing than it needs to be

[ypisetsky]

Please complete the information below:

Where is the problem?

The documentation for the Pair class is very confusing.

What is the problem?

The Pair class is a tuple with two elements. That it happens to implement collection interfaces shouldn't detract from that. Saying that it's really an ImmVector while also saying that it supports $x[] syntax for appending is just confusing. Also it's probably a good idea to document the functions that return the same values (i.e. firstKey() should always return 0 for a Pair) to help make it fit together.

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Please don't change anything below this point.

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• Build ID: 2016-03-25T19:44:16+0000:59945858b91b58253f39c91d5ff11f685e228917:ded7f690201f02c37531b00bb6a6fc0091e9945e
• Page requested: /hack/reference/class/HH.Pair/
• Page requested at: Fri, 25 Mar 2016 20:39:40 +0000
• Controller: APIGenericPageController

[fredemmott]

That said, any rewording should make it clear that it does not act like tuples - in particular, it has object (byref) semantics instead of value semantics.