30 Input/output library [input.output]

30.10 File systems [filesystems]

30.10.9 Enumerations [fs.enum]

30.10.9.5 Enum class perm_­options [fs.enum.perm.opts]

The enum class type perm_­options is a bitmask type ([bitmask.types]) that specifies bitmask constants used to control the semantics of permissions operations, with the meanings listed in Table 126.
The bitmask constants are bitmask elements.
In Table 126 perm denotes a value of type perms passed to permissions.
Table 126 — Enum class perm_­options
Name
Meaning
replace
permissions shall replace the file's permission bits with perm
add
permissions shall replace the file's permission bits with the bitwise OR of perm and the file's current permission bits.
remove
permissions shall replace the file's permission bits with the bitwise AND of the complement of perm and the file's current permission bits.
nofollow
permissions shall change the permissions of a symbolic link itself rather than the permissions of the file the link resolves to.