Struct core::fmt::Error

pub struct Error;

The error type which is returned from formatting a message into a stream.

This type does not support transmission of an error other than that an error occurred. This is because, despite the existence of this error, string formatting is considered an infallible operation. fmt() implementors should not return this Error unless they received it from their Formatter. The only time your code should create a new instance of this error is when implementing fmt::Write, in order to cancel the formatting operation when writing to the underlying stream fails.

Any extra information must be arranged to be transmitted through some other means, such as storing it in a field to be consulted after the formatting operation has been cancelled. (For example, this is how std::io::Write::write_fmt() propagates IO errors during writing.)

This type, fmt::Error, should not be confused with std::io::Error or std::error::Error, which you may also have in scope.

Examples

use std::fmt::{self, write};

let mut output = String::new();
if let Err(fmt::Error) = write(&mut output, format_args!("Hello {}!", "world")) {
    panic!("An error occurred");
}

Trait Implementations

impl Clone for Error

fn clone(&self) -> Error

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Error

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Error

fn default() -> Error

Returns the “default value” for a type.

impl Display for Error

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for Error

fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

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

👎Deprecated since 1.33.0: replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access #99301)

Provides type-based access to context intended for error reports.

impl Hash for Error

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H: Hasher>(data: &[Self], state: &mut H)

where Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for Error

fn cmp(&self, other: &Error) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl PartialEq for Error

fn eq(&self, other: &Error) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Error

fn partial_cmp(&self, other: &Error) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Copy for Error

impl Eq for Error

impl StructuralPartialEq for Error