cpp/filesystem/permissions

Changes access permissions of the file to which resolves, as if by POSIX. Symlinks are followed unless is set in.

The second signature behaves as if called with set to.

The effects depend on and  as follows:


 * If is, file permissions are set to exactly  (meaning, every valid bit of  is applied)
 * If is, the file permissions are set to exactly  (meaning, any valid bit that is set in , but not in the file's current permissions is added to the file's permissions)
 * If is, the file permissions are set to exactly  (meaning, any valid bit that is clear in , but set in the file's current permissions is cleared in the file's permissions)

is required to have only one of, , or to be set.

The non-throwing overload has no special action on error.

Return value
(none)