CsvResult!bool indicating success or ioFailure on error.CsvResult!bool open()Open the file according to the selected mode.
Notes:
read, the file must exist; failure is surfaced via CsvResult with ioFailure.write, the file is created or truncated.append, the file is created if it does not exist.memoryMapped == true, mapping is not performed here; this methodonly opens the OS file handle and validates access.
CsvResult!bool indicating success or ioFailure on error.