[Issue 15682] Implement efficient setops for builtin AAs

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15682

ZombineDev <petar.p.kirov at gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
                 CC|                            |petar.p.kirov at gmail.com
         Resolution|REMIND                      |---
            Summary|concat associative arrays   |Implement efficient setops
                   |                            |for builtin AAs

--- Comment #1 from ZombineDev <petar.p.kirov at gmail.com> ---
Currently, Phobos provides setops only for sorted ranges
(http://dlang.org/phobos/std_algorithm_setops).
It would be great if druntime could expose primitives that would allow
efficient set operations over builtin AAs, including concatenation (set union),
as per OP.

As buitin AAs are implemented as hash tables (i.e. they are unordered) it is
not possible to implement efficiently set operations only using the byKey,
byValue and byKeyValue, etc. ranges.

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