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From: "nimrodcowboy at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug c++/106223] difference in behaviour between no optimization and
 -O for specialization of std::forward
Date: Thu, 07 Jul 2022 16:02:11 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D106223

--- Comment #8 from Nimrod <nimrodcowboy at gmail dot com> ---
(In reply to Jonathan Wakely from comment #6)
> (In reply to Nimrod from comment #4)
> > https://timsong-cpp.github.io/cppwp/n4659/func.require#3
> > "...A forwarding call wrapper is a call wrapper that can be called with=
 an
>=20
> This is irrelevant, std::forward isn't a call wrapper.
Yes. In which context, what I want to prove is the wording about "forwardin=
g"
in the standard isn't related to the value of the object. I was thinking I =
can
provide a better example without ruining the std::forward implementation. I
just add a log in the specialization of std::forward and do nothing else. (=
to
record A is being "forwarded")
like,=20

template<>
A&& forward(A& a) noexcept {
    std::cout << "recorded\n";
    return std::move(a);
}

I don't think this example will bring more help in this discussion. I was
trying to reproduce some more cases using std::swap but failed.=20

> Anyway, specializing any function template from namespace std is explicit=
ly
> forbidden since C++20, because it's not necessary or sensible to do it.

Ok. It's fair to me. A little off-topic question, what's the GCC's attitude=
 to
features with defects being fixed in newer standards? Will GCC still support
them as the older standard says?=