[Bug libstdc++/114244] Need to use round when parsing fractional seconds

[howard.hinnant at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114244

--- Comment #4 from Howard Hinnant <howard.hinnant at gmail dot com> ---
Not positive (because I don't know your code that well), but I think:

              __s = round<_Duration>(__fs);

will do it.