Re: [Boost-users] [multi_index_container] Using equal_range with hashed indices

Subject: Re: [Boost-users] [multi_index_container] Using equal_range with hashed indices
From: Joaquin M LópezMuñoz (joaquin_at_[hidden])
Date: 2015-09-28 02:17:33

Muruganand Karthikeyan <muruthegun <at> gmail.com> writes:

> Hello!
>
> std::equal_range requires that the container be pre-sorted
> (http://www.cplusplus.com/reference/algorithm/equal_range/)
> How does multi-index container handle this scenario with respect
> to hashed non-unique indices. 

Hashed indices' equal_range works on sequences that have no
particular order (other than equivalent elements being adjacent),
which is fine because it does *not* use std::equal_range internally
but its own logic (much as, say, std::unordered_set::equal_range).

> The reason I ask is since I'm facing a situation with equal_range.
> Please see below code -
>
> [...]
> typedef UserIdContainer::index<id1_id2>::type IndexById1Id2;
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