1.0.0[][src]Struct std::string::FromUtf8Error

pub struct FromUtf8Error { /* fields omitted */ }

A possible error value when converting a String from a UTF-8 byte vector.

This type is the error type for the from_utf8 method on String. It is designed in such a way to carefully avoid reallocations: the into_bytes method will give back the byte vector that was used in the conversion attempt.

The Utf8Error type provided by std::str represents an error that may occur when converting a slice of u8s to a &str. In this sense, it's an analogue to FromUtf8Error, and you can get one from a FromUtf8Error through the utf8_error method.

Examples

Basic usage:

// some invalid bytes, in a vector
let bytes = vec![0, 159];

let value = String::from_utf8(bytes);

assert!(value.is_err());
assert_eq!(vec![0, 159], value.unwrap_err().into_bytes());Run

Methods

impl FromUtf8Error[src]

Important traits for &'_ [u8]
pub fn as_bytes(&self) -> &[u8]1.26.0[src]

Returns a slice of u8s bytes that were attempted to convert to a String.

Examples

Basic usage:

// some invalid bytes, in a vector
let bytes = vec![0, 159];

let value = String::from_utf8(bytes);

assert_eq!(&[0, 159], value.unwrap_err().as_bytes());Run

Important traits for Vec<u8>
pub fn into_bytes(self) -> Vec<u8>[src]

Returns the bytes that were attempted to convert to a String.

This method is carefully constructed to avoid allocation. It will consume the error, moving out the bytes, so that a copy of the bytes does not need to be made.

Examples

Basic usage:

// some invalid bytes, in a vector
let bytes = vec![0, 159];

let value = String::from_utf8(bytes);

assert_eq!(vec![0, 159], value.unwrap_err().into_bytes());Run

pub fn utf8_error(&self) -> Utf8Error[src]

Fetch a Utf8Error to get more details about the conversion failure.

The Utf8Error type provided by std::str represents an error that may occur when converting a slice of u8s to a &str. In this sense, it's an analogue to FromUtf8Error. See its documentation for more details on using it.

Examples

Basic usage:

// some invalid bytes, in a vector
let bytes = vec![0, 159];

let error = String::from_utf8(bytes).unwrap_err().utf8_error();

// the first byte is invalid here
assert_eq!(1, error.valid_up_to());Run

Trait Implementations

impl Display for FromUtf8Error[src]

impl Debug for FromUtf8Error[src]

impl Error for FromUtf8Error[src]

fn cause(&self) -> Option<&dyn Error>[src]

Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

The lower-level cause of this error, if any. Read more

fn source(&self) -> Option<&(dyn Error + 'static)>1.30.0[src]

The lower-level source of this error, if any. Read more

Auto Trait Implementations

impl UnwindSafe for FromUtf8Error

impl RefUnwindSafe for FromUtf8Error

impl Unpin for FromUtf8Error

impl Send for FromUtf8Error

impl Sync for FromUtf8Error

Blanket Implementations

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

impl<T> From<T> for T[src]

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

impl<T> Borrow<T> for T where
    T: ?Sized
[src]

impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

impl<T> Any for T where
    T: 'static + ?Sized
[src]

impl<T> ToString for T where
    T: Display + ?Sized
[src]