[fs.op.last.write.time]
31 Input/output library [input.output]
31.12 File systems [filesystems]
31.12.13 Filesystem operation functions [fs.op.funcs]
31.12.13.26 Last write time [fs.op.last.write.time]
file_time_type filesystem::last_write_time(const path& p);
file_time_type filesystem::last_write_time(const path& p, error_code& ec) noexcept;
Returns: The time of last data modification of p, determined as if by the value of the POSIX stat class member st_mtime obtained as if by POSIX stat.
The signature with argument ec returns file_time_type::min() if an error occurs.
void filesystem::last_write_time(const path& p, file_time_type new_time);
void filesystem::last_write_time(const path& p, file_time_type new_time,
error_code& ec) noexcept;