commons-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Thomas Neidhart (JIRA)" <>
Subject [jira] [Commented] (COLLECTIONS-504) CompositeMap should support compositing of maps of derived types
Date Wed, 04 Dec 2013 15:33:35 GMT


Thomas Neidhart commented on COLLECTIONS-504:

What you proposed makes sense, but is not possible atm.

In case you would like to see Immutable collections also in Apache Commons Collections you
could already create a feature request.
I think there are surely use-cases for them and the memory savings can be crucial in various

> CompositeMap should support compositing of maps of derived types
> ----------------------------------------------------------------
>                 Key: COLLECTIONS-504
>                 URL:
>             Project: Commons Collections
>          Issue Type: Bug
>          Components: Map
>    Affects Versions: 4.0
>            Reporter: Peter Cooper Jr.
>            Priority: Minor
> I'm attempting to composite two maps, one of which is a {{Map<String, String>}}
and the other of which is a {{Map<String, Object>}}. I would have expected that I could
composite them into a {{CompositeMap<String, Object>}}, but the constructors of CompositeMap
expect all of the maps being composited to have exactly the same type arguments.
> That is, I think the constructors should take arguments of {{Map<? extends K, ? extends
V>}} instead of what they currently have of {{Map<K, V>}}, much like most collection
methods, since there shouldn't be a problem accepting type arguments that are subtypes of
the composite map types.
> Thanks!

This message was sent by Atlassian JIRA

View raw message