27 Input/output library [input.output]

[ Note: The format conversions described in this section are not applied on POSIX- or Windows-based operating systems because on these systems:

• (1.1)

  The generic format is acceptable as a native path.

• (1.2)

  There is no need to distinguish between native format and generic format in function arguments.

• (1.3)

  Paths for regular files and paths for directories share the same syntax.

 — end note ]

Function arguments that take character sequences representing paths may use the generic pathname format grammar ([path.generic]) or the native pathname format ([fs.def.native]). If and only if such arguments are in the generic format and the generic format is not acceptable to the operating system as a native path, conversion to native format shall be performed during the processing of the argument.

[ Note: Some operating systems may have no unambiguous way to distinguish between native format and generic format arguments. This is by design as it simplifies use for operating systems that do not require disambiguation. An implementation for an operating system where disambiguation is required is permitted to distinguish between the formats.  — end note ]

If the native format requires paths for regular files to be formatted differently from paths for directories, the path shall be treated as a directory path if its last element is a directory-separator, otherwise it shall be treated as a path to a regular file.