29 Input/output library [input.output]

error_code ec;
file_status result = status(p, ec);
if (result.type() == file_type::none)
  throw filesystem_error(implementation-supplied-message, p, ec);
return result;

• (6.1)
  If ec != error_­code():
  • (6.1.1)
    If the specific error indicates that p cannot be resolved because some element of the path does not exist, returns file_­status(file_­type​::​not_­found).
  • (6.1.2)
    Otherwise, if the specific error indicates that p can be resolved but the attributes cannot be determined, returns file_­status(file_­type​::​unknown).
  • (6.1.3)
    Otherwise, returns file_­status(file_­type​::​none).
  [ Note

  : These semantics distinguish between p being known not to exist, p existing but not being able to determine its attributes, and there being an error that prevents even knowing if p exists. These distinctions are important to some use cases. — end note

   ]
• (6.2)
  Otherwise,
  • (6.2.1)
    If the attributes indicate a regular file, as if by POSIX S_­ISREG, returns file_­status(file_­type​::​regular, prms).
    [ Note

    : file_­type​::​regular implies appropriate <fstream> operations would succeed, assuming no hardware, permission, access, or file system race errors. Lack of file_­type​::​regular does not necessarily imply <fstream> operations would fail on a directory. — end note

     ]
  • (6.2.2)
    Otherwise, if the attributes indicate a directory, as if by POSIX S_­ISDIR, returns file_­status(file_­type​::​directory, prms).
    [ Note

    : file_­type​::​directory implies that calling directory_­iterator(p) would succeed. — end note

     ]
  • (6.2.3)
    Otherwise, if the attributes indicate a block special file, as if by POSIX S_­ISBLK, returns file_­status(file_­type​::​block, prms).
  • (6.2.4)
    Otherwise, if the attributes indicate a character special file, as if by POSIX S_­ISCHR, returns file_­status(file_­type​::​character, prms).
  • (6.2.5)
    Otherwise, if the attributes indicate a fifo or pipe file, as if by POSIX S_­ISFIFO, returns file_­status(file_­type​::​fifo, prms).
  • (6.2.6)
    Otherwise, if the attributes indicate a socket, as if by POSIX S_­ISSOCK, returns file_­status(file_­type​::​socket, prms).
  • (6.2.7)
    Otherwise, if the attributes indicate an implementation-defined file type ([fs.enum.file.type]), returns file_­status(file_­type​::​A, prms), where A is the constant for the implementation-defined file type.
  • (6.2.8)
    Otherwise, returns file_­status(file_­type​::​unknown, prms).