# Struct alloc::fmt::Error

1.0.0 · source · [−]

    pub struct Error;

Expand description

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. Any extra information must be arranged to be transmitted through some other means.

An important thing to remember is that the 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");
    }

Run

## Trait Implementations

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### impl Clone for Error

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#### fn clone(&self) -> Error

Returns a copy of the value. Read more
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#### fn clone_from(&mut self, source: &Self)

Performs copy-assignment from `source`. Read more
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### impl Debug for Error

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

Formats the value using the given formatter. Read more
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### impl Default for Error

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#### fn default() -> Error

Returns the “default value” for a type. Read more
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### impl Display for Error

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

Formats the value using the given formatter. Read more
1.11.0 · source

### impl Error for Error

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#### fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()
Read more
1.30.0 · source

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

The lower-level source of this error, if any. Read more
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#### fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0: replaced by Error::source, which can support downcasting
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#### fn provide(&'a self, demand: &mut Demand<'a>)

🔬This is a nightly-only experimental API. (`error_generic_member_access` #99301)
Provides type based access to context intended for error reports. Read more
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### impl Hash for Error

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

Feeds this value into the given `Hasher`. Read more
1.3.0 · source

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

Feeds a slice of this type into the given `Hasher`. Read more
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### impl Ord for Error

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

This method returns an `Ordering` between `self` and `other`. Read more
1.21.0 · source

#### fn max(self, other: Self) -> Selfwhere
Self: Sized,

Compares and returns the maximum of two values. Read more
1.21.0 · source

#### fn min(self, other: Self) -> Selfwhere
Self: Sized,

Compares and returns the minimum of two values. Read more
1.50.0 · source

#### fn clamp(self, min: Self, max: Self) -> Selfwhere
Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval. Read more
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### impl PartialEq<Error> for Error

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

This method tests for `self` and `other` values to be equal, and is used by `==`. Read more
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#### fn ne(&self, other: &Rhs) -> bool

This method tests for `!=`. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more
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### impl PartialOrd<Error> for Error

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

This method returns an ordering between `self` and `other` values if one exists. Read more
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#### fn lt(&self, other: &Rhs) -> bool

This method tests less than (for `self` and `other`) and is used by the `<` operator. Read more
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#### fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for `self` and `other`) and is used by the `<=` operator. Read more
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#### fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for `self` and `other`) and is used by the `>` operator. Read more
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#### fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for `self` and `other`) and is used by the `>=` operator. Read more
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### impl Copy for Error

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### impl Eq for Error

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### impl StructuralEq for Error

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### impl StructuralPartialEq for Error

## Auto Trait Implementations

### impl RefUnwindSafe for Error

### impl Send for Error

### impl Sync for Error

### impl Unpin for Error

### impl UnwindSafe for Error

## Blanket Implementations

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### impl<T> Any for Twhere
T: 'static + ?Sized,

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#### fn type_id(&self) -> TypeId

Gets the `TypeId` of `self`. Read more
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### impl<T> Borrow<T> for Twhere
T: ?Sized,

const: unstable · source

#### fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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### impl<T> BorrowMut<T> for Twhere
T: ?Sized,

const: unstable · source

#### fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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### impl<T> From<T> for T

const: unstable · source

#### fn from(t: T) -> T

Returns the argument unchanged.

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### impl<T, U> Into<U> for Twhere
U: From<T>,

const: unstable · source

#### fn into(self) -> U

Calls `U::from(self)`.

That is, this conversion is whatever the implementation of `From<T> for U` chooses to do.

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### impl<E> Provider for Ewhere
E: Error + ?Sized,

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#### fn provide(&'a self, demand: &mut Demand<'a>)

🔬This is a nightly-only experimental API. (`provide_any` #96024)
Data providers should implement this method to provide all values they are able to provide by using `demand`. Read more
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### impl<T> ToOwned for Twhere
T: Clone,

#### type Owned = T

The resulting type after obtaining ownership.
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#### fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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#### fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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### impl<T> ToString for Twhere
T: Display + ?Sized,

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#### default fn to_string(&self) -> String

Converts the given value to a `String`. Read more
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### impl<T, U> TryFrom<U> for Twhere
U: Into<T>,

#### type Error = Infallible

The type returned in the event of a conversion error.
const: unstable · source

#### fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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### impl<T, U> TryInto<U> for Twhere
U: TryFrom<T>,

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

The type returned in the event of a conversion error.
const: unstable · source

#### fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.