30 Input/output library [input.output]

30.10 File systems [filesystems]

30.10.15 Filesystem operation functions [fs.op.funcs]

30.10.15.25 Last write time [fs.op.last_write_time]

file_time_type last_write_time(const path& p); file_time_type 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 structure member st_­mtime obtained as if by POSIX stat(). The signature with argument ec returns file_­time_­type​::​min() if an error occurs.

Throws: As specified in [fs.err.report].

void last_write_time(const path& p, file_time_type new_time); void last_write_time(const path& p, file_time_type new_time, error_code& ec) noexcept;

Effects: Sets the time of last data modification of the file resolved to by p to new_­time, as if by POSIX futimens().

Throws: As specified in [fs.err.report].

[Note: A postcondition of last_­write_­time(p) == new_­time is not specified since it might not hold for file systems with coarse time granularity. end note]