pub struct Utf8Error { /* fields omitted */ }
Errors which can occur when attempting to interpret a sequence of u8 as a string.
As such, the from_utf8 family of functions and methods for both Strings and &strs make use of this error, for example.
This error type’s methods can be used to create functionality similar to String::from_utf8_lossy without allocating heap memory:
fn from_utf8_lossy<F>(mut input: &[u8], mut push: F) where F: FnMut(&str) {
loop {
match std::str::from_utf8(input) {
Ok(valid) => {
push(valid);
break
}
Err(error) => {
let (valid, after_valid) = input.split_at(error.valid_up_to());
unsafe {
push(std::str::from_utf8_unchecked(valid))
}
push("\u{FFFD}");
if let Some(invalid_sequence_length) = error.error_len() {
input = &after_valid[invalid_sequence_length..]
} else {
break
}
}
}
}
}impl Utf8Error[src]
pub fn valid_up_to(&self) -> usize[src]1.5.0
Returns the index in the given string up to which valid UTF-8 was verified.
It is the maximum index such that from_utf8(&input[..index]) would return Ok(_).
Basic usage:
use std::str; // some invalid bytes, in a vector let sparkle_heart = vec![0, 159, 146, 150]; // std::str::from_utf8 returns a Utf8Error let error = str::from_utf8(&sparkle_heart).unwrap_err(); // the second byte is invalid here assert_eq!(1, error.valid_up_to());
pub fn error_len(&self) -> Option<usize>[src]1.20.0
Provides more information about the failure:
None: the end of the input was reached unexpectedly. self.valid_up_to() is 1 to 3 bytes from the end of the input. If a byte stream (such as a file or a network socket) is being decoded incrementally, this could be a valid char whose UTF-8 byte sequence is spanning multiple chunks.
Some(len): an unexpected byte was encountered. The length provided is that of the invalid byte sequence that starts at the index given by valid_up_to(). Decoding should resume after that sequence (after inserting a U+FFFD REPLACEMENT CHARACTER) in case of lossy decoding.
impl Clone for Utf8Error[src]
impl Copy for Utf8Error[src]
impl Debug for Utf8Error[src]
impl Display for Utf8Error[src]
impl Eq for Utf8Error[src]
impl Error for Utf8Error[src]
fn description(&self) -> &str[src]
fn source(&self) -> Option<&(dyn Error + 'static)>[src]1.30.0
fn backtrace(&self) -> Option<&Backtrace>[src]
fn cause(&self) -> Option<&dyn Error>[src]
impl PartialEq<Utf8Error> for Utf8Error[src]
impl StructuralEq for Utf8Error[src]
impl StructuralPartialEq for Utf8Error[src]
impl RefUnwindSafe for Utf8Errorimpl Send for Utf8Errorimpl Sync for Utf8Errorimpl Unpin for Utf8Errorimpl UnwindSafe for Utf8Errorimpl<T> Any for T where
T: 'static + ?Sized, [src]
impl<T> Borrow<T> for T where
T: ?Sized, [src]
fn borrow(&self) -> &TⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized,
type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized,
type Item = <I as Iterator>::Item;
impl<R: Read + ?Sized, '_> Read for &'_ mut R
impl<W: Write + ?Sized, '_> Write for &'_ mut W
[src]
impl<T> BorrowMut<T> for T where
T: ?Sized, [src]
fn borrow_mut(&mut self) -> &mut TⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized,
type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized,
type Item = <I as Iterator>::Item;
impl<R: Read + ?Sized, '_> Read for &'_ mut R
impl<W: Write + ?Sized, '_> Write for &'_ mut W
[src]
impl<T> From<T> for T[src]
impl<T, U> Into<U> for T where
U: From<T>, [src]
impl<T> ToOwned for T where
T: Clone, [src]
type Owned = TThe resulting type after obtaining ownership.
fn to_owned(&self) -> T[src]
fn clone_into(&self, target: &mut T)[src]
impl<T> ToString for T where
T: Display + ?Sized, [src]
impl<T, U> TryFrom<U> for T where
U: Into<T>, [src]
type Error = InfallibleThe type returned in the event of a conversion error.
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>[src]
impl<T, U> TryInto<U> for T where
U: TryFrom<T>, [src]
© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/str/struct.Utf8Error.html