Struct CapacityError 

pub struct CapacityError<T> {
    pub capacity: SizeHint,
    pub kind: CapacityErrorKind<T>,
}

An error indicating that a collection or extension operation failed because of a conflict between the collection’s capacity and the number of items produced by an Iterator.

This error represents three failure modes, identified by CapacityError::kind.

• CapacityErrorKind::Bounds — the iterator’s reported size bounds are incompatible with the required capacity, making the operation impossible to satisfy even before iteration begins.

• CapacityErrorKind::Underflow — the iterator produced fewer items than the minimum required by the capacity.

• CapacityErrorKind::Overflow — the iterator produced more items than the maximum allowed by the capacity. The item that caused the overflow is preserved, and may be recovered via ErrorItemProvider. The number of overflowing items is implied to be at least one, but may be more.

Type Parameters

• T: The type of the item in the collection.

Fields

capacity: SizeHint

The capacity constraint that was violated.

kind: CapacityErrorKind<T>

The specific kind of capacity mismatch that occurred.

Implementations

impl<T> CapacityError<T>

pub const fn bounds(capacity: SizeHint, hint: SizeHint) -> Self

Creates a new Bounds CapacityError indicating that hint bounds are incompatible with capacity.

Arguments

• capacity - the capacity of the collection
• hint - the size hint of the iterator

Panics

Panics if capacity and hint overlap.

Examples

let err = CapacityError::<i32>::bounds(SizeHint::exact(5), SizeHint::exact(2));

assert_eq!(err.capacity, SizeHint::exact(5));
assert_eq!(err.kind, CapacityErrorKind::Bounds { hint: SizeHint::exact(2) });

pub fn ensure_fits<I: Iterator<Item = T>>( iter: &I, capacity: SizeHint, ) -> Result<(), Self>

Ensures that iter’s size_hint overlaps capacity.

Arguments

• iter - the Iterator to check.
• capacity - the capacity of the collection

Errors

Returns a Bounds CapacityError if iter’s size_hint is disjoint with cap.

Panics

Panics if iter’s size_hint is invalid.

Examples

CapacityError::<i32>::ensure_fits(&(1..=5), SizeHint::at_most(5)).expect("Should fit");

let err = CapacityError::<i32>::ensure_fits(&(1..=5), SizeHint::at_most(4))
    .expect_err("Should fit");

assert_eq!(err.capacity, SizeHint::at_most(4));
assert_eq!(err.kind, CapacityErrorKind::Bounds { hint: SizeHint::exact(5) });

pub const fn overflow(capacity: SizeHint, overflow: T) -> Self

Creates a new CapacityError indicating that the collection overflowed capacity.

Arguments

• capacity - The capacity that overflowed.
• overflow - The item that overflowed capacity.

Panics

Panics if capacity is not bounded.

Examples

let err = CapacityError::overflow(SizeHint::exact(5), 2);

assert_eq!(err.capacity, SizeHint::exact(5));
assert_eq!(err.kind, CapacityErrorKind::Overflow { overflow: 2 });

pub const fn underflow(capacity: SizeHint, count: usize) -> Self

Creates a new CapacityError indicating that fewer items were produced than the minimum required by capacity.

Arguments

• capacity - The capacity that was underflowed.
• count - The number of items that were produced.

Panics

Panics if count is greater than or equal to capacity.lower().

Examples

let err = CapacityError::<i32>::underflow(SizeHint::exact(5), 2);

assert_eq!(err.capacity, SizeHint::exact(5));
assert_eq!(err.kind, CapacityErrorKind::Underflow { count: 2 });

pub const fn underflow_of<C: FixedCap>(count: usize) -> Self

Creates a new CapacityError indicating that fewer items were produced than the minimum required by C’s FixedCap::CAP.

Arguments

• count - The number of items that were produced.

Type Parameters

• C - A collection with a fixed capaciy.

Examples

let err = CapacityError::<i32>::underflow_of::<[i32; 5]>(2);

assert_eq!(err.capacity, SizeHint::exact(5));
assert_eq!(err.kind, CapacityErrorKind::Underflow { count: 2 });

Trait Implementations

impl<T: Debug> Debug for CapacityError<T>

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

Formats the value using the given formatter.

impl<T> Display for CapacityError<T>

where CapacityErrorKind<T>: Display,

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

Formats the value using the given formatter.

impl<T> Error for CapacityError<T>

where Self: Debug + Display,

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

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

fn description(&self) -> &str

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

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)

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

impl<T> ErrorItemProvider for CapacityError<T>

type Item = T

The type of the item that may be contained in this error.

fn into_item(self) -> Option<Self::Item>

Consumes the error and returns the rejected item, if any.

fn item(&self) -> Option<&Self::Item>

Returns a reference to the rejected item, if any.

impl<T> From<CapacityError<T>> for CapacityError<T>

Available on crate feature arrayvec only.

fn from(err: CapacityError<T>) -> Self

Converts to this type from the input type.

impl<T: PartialEq> PartialEq for CapacityError<T>

fn eq(&self, other: &CapacityError<T>) -> 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<T: Eq> Eq for CapacityError<T>

impl<T> StructuralPartialEq for CapacityError<T>