diff options
Diffstat (limited to 'src/libcore')
| -rw-r--r-- | src/libcore/fmt/mod.rs | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/src/libcore/fmt/mod.rs b/src/libcore/fmt/mod.rs index 80c661b260c..85226444e84 100644 --- a/src/libcore/fmt/mod.rs +++ b/src/libcore/fmt/mod.rs @@ -83,6 +83,23 @@ pub trait Write { #[stable(feature = "rust1", since = "1.0.0")] fn write_str(&mut self, s: &str) -> Result; + /// Writes a `char` into this writer, returning whether the write succeeded. + /// + /// A single `char` may be encoded as more than one byte. + /// This method can only succeed if the entire byte sequence was successfully + /// written, and this method will not return until all data has been + /// written or an error occurs. + /// + /// # Errors + /// + /// This function will return an instance of `FormatError` on error. + #[stable(feature = "rust1", since = "1.0.0")] + fn write_char(&mut self, c: char) -> Result { + let mut utf_8 = [0u8; 4]; + let bytes_written = c.encode_utf8(&mut utf_8).unwrap_or(0); + self.write_str(unsafe { mem::transmute(&utf_8[..bytes_written]) }) + } + /// Glue for usage of the `write!` macro with implementers of this trait. /// /// This method should generally not be invoked manually, but rather through |