| // run-pass |
| |
| #![feature(io_error_uncategorized)] |
| |
| use std::fmt; |
| use std::io::{self, Error, Write, sink}; |
| |
| struct ErrorDisplay; |
| |
| impl fmt::Display for ErrorDisplay { |
| fn fmt(&self, _: &mut fmt::Formatter) -> fmt::Result { |
| Err(fmt::Error) |
| } |
| } |
| |
| struct ErrorWriter; |
| |
| const FORMAT_ERROR: io::ErrorKind = io::ErrorKind::Uncategorized; |
| const WRITER_ERROR: io::ErrorKind = io::ErrorKind::NotConnected; |
| |
| impl Write for ErrorWriter { |
| fn write(&mut self, _buf: &[u8]) -> io::Result<usize> { |
| Err(Error::new(WRITER_ERROR, "not connected")) |
| } |
| |
| fn flush(&mut self) -> io::Result<()> { Ok(()) } |
| } |
| |
| fn main() { |
| // Test that the error from the formatter is propagated. |
| let res = write!(sink(), "{} {} {}", 1, ErrorDisplay, "bar"); |
| assert!(res.is_err(), "formatter error did not propagate"); |
| assert_eq!(res.unwrap_err().kind(), FORMAT_ERROR); |
| |
| // Test that an underlying error is propagated |
| let res = write!(ErrorWriter, "abc"); |
| assert!(res.is_err(), "writer error did not propagate"); |
| |
| // Writer error |
| let res = write!(ErrorWriter, "abc {}", ErrorDisplay); |
| assert!(res.is_err(), "writer error did not propagate"); |
| assert_eq!(res.unwrap_err().kind(), WRITER_ERROR); |
| |
| // Formatter error |
| let res = write!(ErrorWriter, "{} abc", ErrorDisplay); |
| assert!(res.is_err(), "formatter error did not propagate"); |
| assert_eq!(res.unwrap_err().kind(), FORMAT_ERROR); |
| } |