[Bug libstdc++/81122] [DR 2381] parsing f stopped after '0' when reading std::hexfloat >> f;

[maxim.yegorushkin at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81122

--- Comment #19 from Maxim Egorushkin <maxim.yegorushkin at gmail dot com> ---
(In reply to Jonathan Wakely from comment #17)

> At this time LWG 2381 is still open. Until the proposed fix (or some other
> fix) is resolved by making a change to the draft standard, I do not want to
> change libstdc++.

May be enable hexfloat round-trip if a user defines a macro?

The standards often follow existing practice, waiting on the standard may lead
to a deadlock.