From: Marek Polacek <polacek@redhat.com>
To: Tim Lange <mail@tim-lange.me>
Cc: GCC Mailing List <gcc@gcc.gnu.org>
Subject: Re: Usage of the C++ stdlib unordered_map in GCC
Date: Tue, 30 Aug 2022 16:07:48 -0400 [thread overview]
Message-ID: <Yw5uFAZeTmhJV6LC@redhat.com> (raw)
In-Reply-To: <942GHR.WGPY8O255349@tim-lange.me>
On Tue, Aug 30, 2022 at 09:57:45PM +0200, Tim Lange wrote:
> Hello,
>
> I was preparing a patch for GCC and used the unordered_map from the C++
> stdlib in my patch. Later on, I noticed that it is used nowhere else inside
> GCC except for some files in the go frontend.
>
> I wondered, now that building GCC requires a C++11 host compiler, whether
> there is a consensus on which data structure implementation is preferred.
> Should I rather use a hash_map instead of an unordered_map or is it on my
> side to decide which one I choose?
I think you're probably better off using a hash_map; std::unordered_map
has efficiency issues as described in
https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p2028r0.pdf
Marek
next prev parent reply other threads:[~2022-08-30 20:07 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-30 19:57 Tim Lange
2022-08-30 20:07 ` Marek Polacek [this message]
2022-08-31 9:37 ` Jonathan Wakely
2022-08-31 14:35 ` Jason Merrill
2022-08-31 14:35 ` Jason Merrill
2022-08-31 15:22 ` Tim Lange
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