31 Input/output library [input.output]

31.12 File systems [filesystems]

31.12.13 Filesystem operation functions [fs.op.funcs]

31.12.13.16 Hard link count [fs.op.hard.lk.ct]

Returns: The number of hard links for p.
The signature with argument ec returns static_cast<uintmax_t>(-1) if an error occurs.
Throws: As specified in [fs.err.report].