Enum gclient::ext::sp_core::sp_std::convert::Infallible

1.34.0 · source ·
pub enum Infallible {}
Expand description

The error type for errors that can never happen.

Since this enum has no variant, a value of this type can never actually exist. This can be useful for generic APIs that use Result and parameterize the error type, to indicate that the result is always Ok.

For example, the TryFrom trait (conversion that returns a Result) has a blanket implementation for all types where a reverse Into implementation exists.

impl<T, U> TryFrom<U> for T where U: Into<T> {
    type Error = Infallible;

    fn try_from(value: U) -> Result<Self, Infallible> {
        Ok(U::into(value))  // Never returns `Err`
    }
}

§Future compatibility

This enum has the same role as the ! “never” type, which is unstable in this version of Rust. When ! is stabilized, we plan to make Infallible a type alias to it:

pub type Infallible = !;

… and eventually deprecate Infallible.

However there is one case where ! syntax can be used before ! is stabilized as a full-fledged type: in the position of a function’s return type. Specifically, it is possible to have implementations for two different function pointer types:

trait MyTrait {}
impl MyTrait for fn() -> ! {}
impl MyTrait for fn() -> std::convert::Infallible {}

With Infallible being an enum, this code is valid. However when Infallible becomes an alias for the never type, the two impls will start to overlap and therefore will be disallowed by the language’s trait coherence rules.

Trait Implementations§

1.34.0 · source§

impl Clone for Infallible

source§

fn clone(&self) -> Infallible

Returns a copy of the value. Read more
1.0.0 · source§

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

Performs copy-assignment from source. Read more
source§

impl<T> Context<T, Infallible> for Option<T>

use anyhow::{Context, Result};

fn maybe_get() -> Option<T> {
    ...
}

fn demo() -> Result<()> {
    let t = maybe_get().context("there is no T")?;
    ...
}
source§

fn context<C>(self, context: C) -> Result<T, Error>
where C: Display + Send + Sync + 'static,

Wrap the error value with additional context.
source§

fn with_context<C, F>(self, context: F) -> Result<T, Error>
where C: Display + Send + Sync + 'static, F: FnOnce() -> C,

Wrap the error value with additional context that is evaluated lazily only once an error does occur.
1.34.0 · source§

impl Debug for Infallible

source§

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

Formats the value using the given formatter. Read more
1.34.0 · source§

impl Display for Infallible

source§

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

Formats the value using the given formatter. Read more
1.8.0 · source§

impl Error for Infallible

source§

fn description(&self) -> &str

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

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

Returns the lower-level source of this error, if any. Read more
1.0.0 · source§

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

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

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

🔬This is a nightly-only experimental API. (error_generic_member_access)
Provides type-based access to context intended for error reports. Read more
1.34.0 · source§

impl From<!> for Infallible

source§

fn from(x: !) -> Infallible

Converts to this type from the input type.
§

impl From<Infallible> for Error

§

fn from(value: Infallible) -> Error

Converts to this type from the input type.
source§

impl From<Infallible> for Error

source§

fn from(err: Infallible) -> Error

Converts to this type from the input type.
§

impl From<Infallible> for ExtrinsicParamsError

§

fn from(value: Infallible) -> ExtrinsicParamsError

Converts to this type from the input type.
1.34.0 · source§

impl From<Infallible> for TryFromIntError

source§

fn from(x: Infallible) -> TryFromIntError

Converts to this type from the input type.
1.36.0 · source§

impl From<Infallible> for TryFromSliceError

source§

fn from(x: Infallible) -> TryFromSliceError

Converts to this type from the input type.
1.44.0 · source§

impl Hash for Infallible

source§

fn hash<H>(&self, _: &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
1.34.0 · source§

impl Ord for Infallible

source§

fn cmp(&self, _other: &Infallible) -> Ordering

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

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

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

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

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

fn clamp(self, min: Self, max: Self) -> Self
where Self: Sized + PartialOrd,

Restrict a value to a certain interval. Read more
1.34.0 · source§

impl PartialEq for Infallible

source§

fn eq(&self, _: &Infallible) -> bool

Tests for self and other values to be equal, and is used by ==.
1.0.0 · source§

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

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

impl PartialOrd for Infallible

source§

fn partial_cmp(&self, _other: &Infallible) -> Option<Ordering>

This method returns an ordering between self and other values if one exists. Read more
1.0.0 · source§

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

Tests less than (for self and other) and is used by the < operator. Read more
1.0.0 · source§

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

Tests less than or equal to (for self and other) and is used by the <= operator. Read more
1.0.0 · source§

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

Tests greater than (for self and other) and is used by the > operator. Read more
1.0.0 · source§

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

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

impl Sequence for Infallible

§

const CARDINALITY: usize = 0usize

Number of values of type Self. Read more
§

fn next(&self) -> Option<Infallible>

Returns value following *self or None if this was the end. Read more
§

fn previous(&self) -> Option<Infallible>

Returns value preceding *self or None if this was the beginning. Read more
§

fn first() -> Option<Infallible>

Returns the first value of type Self. Read more
§

fn last() -> Option<Infallible>

Returns the last value of type Self. Read more
1.61.0 · source§

impl Termination for Infallible

source§

fn report(self) -> ExitCode

Is called to get the representation of the value as status code. This status code is returned to the operating system.
1.34.0 · source§

impl Copy for Infallible

1.34.0 · source§

impl Eq for Infallible

Auto Trait Implementations§

Blanket Implementations§

source§

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

source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
source§

impl<T> Borrow<T> for T
where T: ?Sized,

source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

impl<T> BorrowMut<T> for T
where T: ?Sized,

source§

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

Mutably borrows from an owned value. Read more
§

impl<T> CallHasher for T
where T: Hash + ?Sized,

§

default fn get_hash<H, B>(value: &H, build_hasher: &B) -> u64
where H: Hash + ?Sized, B: BuildHasher,

§

impl<T> CheckedConversion for T

§

fn checked_from<T>(t: T) -> Option<Self>
where Self: TryFrom<T>,

Convert from a value of T into an equivalent instance of Option<Self>. Read more
§

fn checked_into<T>(self) -> Option<T>
where Self: TryInto<T>,

Consume self to return Some equivalent value of Option<T>. Read more
source§

impl<T> CloneToUninit for T
where T: Clone,

source§

default unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
source§

impl<T> CloneToUninit for T
where T: Copy,

source§

unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
§

impl<Q, K> Comparable<K> for Q
where Q: Ord + ?Sized, K: Borrow<Q> + ?Sized,

§

fn compare(&self, key: &K) -> Ordering

Compare self to key and return their ordering.
§

impl<T> Conv for T

§

fn conv<T>(self) -> T
where Self: Into<T>,

Converts self into T using Into<T>. Read more
§

impl<T> Downcast for T
where T: Any,

§

fn into_any(self: Box<T>) -> Box<dyn Any>

Convert Box<dyn Trait> (where Trait: Downcast) to Box<dyn Any>. Box<dyn Any> can then be further downcast into Box<ConcreteType> where ConcreteType implements Trait.
§

fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>

Convert Rc<Trait> (where Trait: Downcast) to Rc<Any>. Rc<Any> can then be further downcast into Rc<ConcreteType> where ConcreteType implements Trait.
§

fn as_any(&self) -> &(dyn Any + 'static)

Convert &Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot generate &Any’s vtable from &Trait’s.
§

fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)

Convert &mut Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot generate &mut Any’s vtable from &mut Trait’s.
§

impl<T> DowncastSync for T
where T: Any + Send + Sync,

§

fn into_any_arc(self: Arc<T>) -> Arc<dyn Any + Send + Sync>

Convert Arc<Trait> (where Trait: Downcast) to Arc<Any>. Arc<Any> can then be further downcast into Arc<ConcreteType> where ConcreteType implements Trait.
source§

impl<T> DynClone for T
where T: Clone,

source§

fn __clone_box(&self, _: Private) -> *mut ()

§

impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

§

fn equivalent(&self, key: &K) -> bool

Checks if this value is equivalent to the given key. Read more
source§

impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

source§

fn equivalent(&self, key: &K) -> bool

Compare self to key and return true if they are equal.
§

impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

§

fn equivalent(&self, key: &K) -> bool

Checks if this value is equivalent to the given key. Read more
§

impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

§

fn equivalent(&self, key: &K) -> bool

Compare self to key and return true if they are equal.
§

impl<T> FmtForward for T

§

fn fmt_binary(self) -> FmtBinary<Self>
where Self: Binary,

Causes self to use its Binary implementation when Debug-formatted.
§

fn fmt_display(self) -> FmtDisplay<Self>
where Self: Display,

Causes self to use its Display implementation when Debug-formatted.
§

fn fmt_lower_exp(self) -> FmtLowerExp<Self>
where Self: LowerExp,

Causes self to use its LowerExp implementation when Debug-formatted.
§

fn fmt_lower_hex(self) -> FmtLowerHex<Self>
where Self: LowerHex,

Causes self to use its LowerHex implementation when Debug-formatted.
§

fn fmt_octal(self) -> FmtOctal<Self>
where Self: Octal,

Causes self to use its Octal implementation when Debug-formatted.
§

fn fmt_pointer(self) -> FmtPointer<Self>
where Self: Pointer,

Causes self to use its Pointer implementation when Debug-formatted.
§

fn fmt_upper_exp(self) -> FmtUpperExp<Self>
where Self: UpperExp,

Causes self to use its UpperExp implementation when Debug-formatted.
§

fn fmt_upper_hex(self) -> FmtUpperHex<Self>
where Self: UpperHex,

Causes self to use its UpperHex implementation when Debug-formatted.
§

fn fmt_list(self) -> FmtList<Self>
where &'a Self: for<'a> IntoIterator,

Formats each item in a sequence. Read more
source§

impl<T> From<!> for T

source§

fn from(t: !) -> T

Converts to this type from the input type.
source§

impl<T> From<T> for T

source§

fn from(t: T) -> T

Returns the argument unchanged.

§

impl<T> FromBits<T> for T

§

fn from_bits(other: T) -> T

Convert other to Self, preserving bitwise representation
§

impl<T> Instrument for T

§

fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided [Span], returning an Instrumented wrapper. Read more
§

fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
source§

impl<T, U> Into<U> for T
where U: From<T>,

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.

source§

impl<T> IntoEither for T

source§

fn into_either(self, into_left: bool) -> Either<Self, Self>

Converts self into a Left variant of Either<Self, Self> if into_left is true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
source§

fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

Converts self into a Left variant of Either<Self, Self> if into_left(&self) returns true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
§

impl<T, Outer> IsWrappedBy<Outer> for T
where Outer: AsRef<T> + AsMut<T> + From<T>, T: From<Outer>,

§

fn from_ref(outer: &Outer) -> &T

Get a reference to the inner from the outer.

§

fn from_mut(outer: &mut Outer) -> &mut T

Get a mutable reference to the inner from the outer.

§

impl<T> Pipe for T
where T: ?Sized,

§

fn pipe<R>(self, func: impl FnOnce(Self) -> R) -> R
where Self: Sized,

Pipes by value. This is generally the method you want to use. Read more
§

fn pipe_ref<'a, R>(&'a self, func: impl FnOnce(&'a Self) -> R) -> R
where R: 'a,

Borrows self and passes that borrow into the pipe function. Read more
§

fn pipe_ref_mut<'a, R>(&'a mut self, func: impl FnOnce(&'a mut Self) -> R) -> R
where R: 'a,

Mutably borrows self and passes that borrow into the pipe function. Read more
§

fn pipe_borrow<'a, B, R>(&'a self, func: impl FnOnce(&'a B) -> R) -> R
where Self: Borrow<B>, B: 'a + ?Sized, R: 'a,

Borrows self, then passes self.borrow() into the pipe function. Read more
§

fn pipe_borrow_mut<'a, B, R>( &'a mut self, func: impl FnOnce(&'a mut B) -> R, ) -> R
where Self: BorrowMut<B>, B: 'a + ?Sized, R: 'a,

Mutably borrows self, then passes self.borrow_mut() into the pipe function. Read more
§

fn pipe_as_ref<'a, U, R>(&'a self, func: impl FnOnce(&'a U) -> R) -> R
where Self: AsRef<U>, U: 'a + ?Sized, R: 'a,

Borrows self, then passes self.as_ref() into the pipe function.
§

fn pipe_as_mut<'a, U, R>(&'a mut self, func: impl FnOnce(&'a mut U) -> R) -> R
where Self: AsMut<U>, U: 'a + ?Sized, R: 'a,

Mutably borrows self, then passes self.as_mut() into the pipe function.
§

fn pipe_deref<'a, T, R>(&'a self, func: impl FnOnce(&'a T) -> R) -> R
where Self: Deref<Target = T>, T: 'a + ?Sized, R: 'a,

Borrows self, then passes self.deref() into the pipe function.
§

fn pipe_deref_mut<'a, T, R>( &'a mut self, func: impl FnOnce(&'a mut T) -> R, ) -> R
where Self: DerefMut<Target = T> + Deref, T: 'a + ?Sized, R: 'a,

Mutably borrows self, then passes self.deref_mut() into the pipe function.
source§

impl<T> Same for T

§

type Output = T

Should always be Self
§

impl<T> SaturatedConversion for T

§

fn saturated_from<T>(t: T) -> Self
where Self: UniqueSaturatedFrom<T>,

Convert from a value of T into an equivalent instance of Self. Read more
§

fn saturated_into<T>(self) -> T
where Self: UniqueSaturatedInto<T>,

Consume self to return an equivalent value of T. Read more
§

impl<T> Tap for T

§

fn tap(self, func: impl FnOnce(&Self)) -> Self

Immutable access to a value. Read more
§

fn tap_mut(self, func: impl FnOnce(&mut Self)) -> Self

Mutable access to a value. Read more
§

fn tap_borrow<B>(self, func: impl FnOnce(&B)) -> Self
where Self: Borrow<B>, B: ?Sized,

Immutable access to the Borrow<B> of a value. Read more
§

fn tap_borrow_mut<B>(self, func: impl FnOnce(&mut B)) -> Self
where Self: BorrowMut<B>, B: ?Sized,

Mutable access to the BorrowMut<B> of a value. Read more
§

fn tap_ref<R>(self, func: impl FnOnce(&R)) -> Self
where Self: AsRef<R>, R: ?Sized,

Immutable access to the AsRef<R> view of a value. Read more
§

fn tap_ref_mut<R>(self, func: impl FnOnce(&mut R)) -> Self
where Self: AsMut<R>, R: ?Sized,

Mutable access to the AsMut<R> view of a value. Read more
§

fn tap_deref<T>(self, func: impl FnOnce(&T)) -> Self
where Self: Deref<Target = T>, T: ?Sized,

Immutable access to the Deref::Target of a value. Read more
§

fn tap_deref_mut<T>(self, func: impl FnOnce(&mut T)) -> Self
where Self: DerefMut<Target = T> + Deref, T: ?Sized,

Mutable access to the Deref::Target of a value. Read more
§

fn tap_dbg(self, func: impl FnOnce(&Self)) -> Self

Calls .tap() only in debug builds, and is erased in release builds.
§

fn tap_mut_dbg(self, func: impl FnOnce(&mut Self)) -> Self

Calls .tap_mut() only in debug builds, and is erased in release builds.
§

fn tap_borrow_dbg<B>(self, func: impl FnOnce(&B)) -> Self
where Self: Borrow<B>, B: ?Sized,

Calls .tap_borrow() only in debug builds, and is erased in release builds.
§

fn tap_borrow_mut_dbg<B>(self, func: impl FnOnce(&mut B)) -> Self
where Self: BorrowMut<B>, B: ?Sized,

Calls .tap_borrow_mut() only in debug builds, and is erased in release builds.
§

fn tap_ref_dbg<R>(self, func: impl FnOnce(&R)) -> Self
where Self: AsRef<R>, R: ?Sized,

Calls .tap_ref() only in debug builds, and is erased in release builds.
§

fn tap_ref_mut_dbg<R>(self, func: impl FnOnce(&mut R)) -> Self
where Self: AsMut<R>, R: ?Sized,

Calls .tap_ref_mut() only in debug builds, and is erased in release builds.
§

fn tap_deref_dbg<T>(self, func: impl FnOnce(&T)) -> Self
where Self: Deref<Target = T>, T: ?Sized,

Calls .tap_deref() only in debug builds, and is erased in release builds.
§

fn tap_deref_mut_dbg<T>(self, func: impl FnOnce(&mut T)) -> Self
where Self: DerefMut<Target = T> + Deref, T: ?Sized,

Calls .tap_deref_mut() only in debug builds, and is erased in release builds.
source§

impl<T> ToOwned for T
where T: Clone,

§

type Owned = T

The resulting type after obtaining ownership.
source§

fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
source§

fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
source§

impl<T> ToString for T
where T: Display + ?Sized,

source§

default fn to_string(&self) -> String

Converts the given value to a String. Read more
§

impl<T> TryConv for T

§

fn try_conv<T>(self) -> Result<T, Self::Error>
where Self: TryInto<T>,

Attempts to convert self into T using TryInto<T>. Read more
source§

impl<T, U> TryFrom<U> for T
where U: Into<T>,

§

type Error = Infallible

The type returned in the event of a conversion error.
source§

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

Performs the conversion.
source§

impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

§

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

The type returned in the event of a conversion error.
source§

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

Performs the conversion.
§

impl<S, T> UncheckedInto<T> for S
where T: UncheckedFrom<S>,

§

fn unchecked_into(self) -> T

The counterpart to unchecked_from.
§

impl<T, S> UniqueSaturatedInto<T> for S
where T: Bounded, S: TryInto<T>,

§

fn unique_saturated_into(self) -> T

Consume self to return an equivalent value of T.
§

impl<V, T> VZip<V> for T
where V: MultiLane<T>,

§

fn vzip(self) -> V

§

impl<T> WithSubscriber for T

§

fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a [WithDispatch] wrapper. Read more
§

fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a [WithDispatch] wrapper. Read more
§

impl<T> CustomError for T
where T: Error + Send + Sync + 'static,

§

impl<T> CustomError for T
where T: Error + Send + Sync + 'static,

§

impl<T> CustomError for T
where T: Error + Send + Sync + 'static,

§

impl<T> Error for T
where T: 'static + Debug + Display + Send + Sync,

§

impl<T> JsonSchemaMaybe for T

§

impl<T> MaybeDebug for T
where T: Debug,

§

impl<T> MaybeDisplay for T
where T: Display,

§

impl<T> MaybeHash for T
where T: Hash,

§

impl<T> MaybeHash for T
where T: Hash,

§

impl<T> MaybeRefUnwindSafe for T
where T: RefUnwindSafe,

§

impl<T> MaybeSend for T
where T: Send,

§

impl<T> MaybeSend for T
where T: Send,

§

impl<T> Member for T
where T: Send + Sync + Debug + Eq + PartialEq + Clone + 'static,