Issues (and possible fix) with Bimap

From: Ignacy Gawedzki (ignacy.gawedzki_at_[hidden])
Date: 2024-08-06 14:50:37

Hi,

I've run into issues with code using Bimap and GCC optimizations.

The description has been submitted both as a bug report to GCC
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115767) and as an issue
in Boost Bimap (https://github.com/boostorg/bimap/issues/43).

While trying to reduce the Bimap code to find a minimal example, I've
found what looks like a proper bug in Bimap and have created a pull
request (https://github.com/boostorg/bimap/pull/45).

It's now been two weeks and the PR is still awaiting approval, so I
thought maybe I better write about it here as well.

I suspect the issues might come from both a bug in GCC optimizations
and from Bimap, because they seem to be gone when I compile with the
latest GCC (which received some optimization-related patches lately)
and the patched Bimap, both on aarch64 and x86_64, but I can't tell
for sure.

Cheers,

Ignacy