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Re: Trying to solve how to do a std::unordered_map<std::pair<..., ...>, ...>

From: Aaron Gray <aaronngray.lists_at_[hidden]>
Date: Mon, 2 Oct 2023 19:57:29 +0100
On Mon, 2 Oct 2023 at 19:27, Giuseppe D'Angelo via Std-Discussion
<std-discussion_at_[hidden]> wrote:
>
> On 02/10/2023 19:45, Aaron Gray via Std-Discussion wrote:
> > size_t hash = 0;
> > hash ^= key.first ? std::hash<string>()( key.first->name ) :
> > std::hash<void *>()( nullptr );
> > hash ^= key.second ? std::hash<string>()( key.second->name ) :
> > std::hash<void *>()( nullptr );
> > return hash;
>
> Please don't do this; Use Boost.HashCombine or one of the techniques
> described by the newer hashing proposals.

Giuseppe,

I am well behind on the C++ Standards now, can you please point me in
the right direction or give me the n numbers of the newer hashing
proposals please ?

Regards,

Aaron



>
> My 2 c,
> --
> Giuseppe D'Angelo
>
> --
> Std-Discussion mailing list
> Std-Discussion_at_[hidden]
> https://lists.isocpp.org/mailman/listinfo.cgi/std-discussion



-- 
Aaron Gray
Independent Open Source Software Engineer, Computer Language
Researcher, Information Theorist, and amateur computer scientist.

Received on 2023-10-02 18:57:48