Struct rustc_pattern_analysis::constructor::IntRange

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pub struct IntRange {
    pub lo: MaybeInfiniteInt,
    pub hi: MaybeInfiniteInt,
}
Expand description

An exclusive interval, used for precise integer exhaustiveness checking. IntRanges always store a contiguous range.

IntRange is never used to encode an empty range or a “range” that wraps around the (offset) space: i.e., range.lo < range.hi.

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§lo: MaybeInfiniteInt§hi: MaybeInfiniteInt

Implementations§

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impl IntRange

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pub fn is_singleton(&self) -> bool

Best effort; will not know that e.g. 255u8.. is a singleton.

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pub fn from_singleton(x: MaybeInfiniteInt) -> IntRange

Construct a singleton range. x must be a Finite(_) value.

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pub fn from_range( lo: MaybeInfiniteInt, hi: MaybeInfiniteInt, end: RangeEnd, ) -> IntRange

Construct a range with these boundaries. lo must not be PosInfinity. hi must not be NegInfinity.

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fn is_subrange(&self, other: &Self) -> bool

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fn intersection(&self, other: &Self) -> Option<Self>

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fn split( &self, column_ranges: impl Iterator<Item = IntRange>, ) -> impl Iterator<Item = (Presence, IntRange)>

Partition a range of integers into disjoint subranges. This does constructor splitting for integer ranges as explained at the top of the file.

This returns an output that covers self. The output is split so that the only intersections between an output range and a column range are inclusions. No output range straddles the boundary of one of the inputs.

Additionally, we track for each output range whether it is covered by one of the column ranges or not.

The following input:

  (--------------------------) // `self`
(------) (----------)    (-)
    (------) (--------)

is first intersected with self:

  (--------------------------) // `self`
  (----) (----------)    (-)
    (------) (--------)

and then iterated over as follows:

  (-(--)-(-)-(------)-)--(-)-

where each sequence of dashes is an output range, and dashes outside parentheses are marked as Presence::Missing.

§isize/usize

Whereas a wildcard of type i32 stands for the range i32::MIN..=i32::MAX, a usize wildcard stands for 0..PosInfinity and a isize wildcard stands for NegInfinity..PosInfinity. In other words, as far as IntRange is concerned, there are values before isize::MIN and after usize::MAX/isize::MAX. This is to avoid e.g. 0..(u32::MAX as usize) from being exhaustive on one architecture and not others. This was decided in https://github.com/rust-lang/rfcs/pull/2591.

These infinities affect splitting subtly: it is possible to get NegInfinity..0 and usize::MAX+1..PosInfinity in the output. Diagnostics must be careful to handle these fictitious ranges sensibly.

Trait Implementations§

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impl Clone for IntRange

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fn clone(&self) -> IntRange

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 IntRange

Note: this will render signed ranges incorrectly. To render properly, convert to a pattern first.

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

Formats the value using the given formatter. Read more
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impl PartialEq for IntRange

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

Tests for self and other values to be equal, and is used by ==.
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fn ne(&self, other: &Rhs) -> bool

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

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impl Eq for IntRange

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impl StructuralPartialEq for IntRange

Auto Trait Implementations§

Blanket Implementations§

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impl<T> Aligned for T

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const ALIGN: Alignment = _

Alignment of Self.
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impl<T> Any for T
where 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> AnyEq for T
where T: Any + PartialEq,

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fn equals(&self, other: &(dyn Any + 'static)) -> bool

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

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impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for T
where T: Copy,

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fn allocate_on<'a>(self, arena: &'a Arena<'tcx>) -> &'a mut T

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fn allocate_from_iter<'a>( arena: &'a Arena<'tcx>, iter: impl IntoIterator<Item = T>, ) -> &'a mut [T]

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impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for T
where T: Copy,

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fn allocate_on<'a>(self, arena: &'a Arena<'tcx>) -> &'a mut T

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fn allocate_from_iter<'a>( arena: &'a Arena<'tcx>, iter: impl IntoIterator<Item = T>, ) -> &'a mut [T]

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

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fn borrow(&self) -> &T

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

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

Mutably borrows from an owned value. Read more
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impl<T> CloneToUninit for T
where T: Clone,

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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
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impl<T, R> CollectAndApply<T, R> for T

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fn collect_and_apply<I, F>(iter: I, f: F) -> R
where I: Iterator<Item = T>, F: FnOnce(&[T]) -> R,

Equivalent to f(&iter.collect::<Vec<_>>()).

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type Output = R

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

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

Checks if this value is equivalent to the given key. Read more
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impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

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

Checks if this value is equivalent to the given key. Read more
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impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

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

Compare self to key and return true if they are equal.
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impl<T> Filterable for T

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fn filterable( self, filter_name: &'static str, ) -> RequestFilterDataProvider<T, fn(_: DataRequest<'_>) -> bool>

Creates a filterable data provider with the given name for debugging. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T> Instrument for T

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

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
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impl<T, U> Into<U> for T
where U: From<T>,

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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<T> IntoEither for T

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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
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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
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impl<P> IntoQueryParam<P> for P

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impl<T> MaybeResult<T> for T

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type Error = !

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fn from(_: Result<T, <T as MaybeResult<T>>::Error>) -> T

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fn to_result(self) -> Result<T, <T as MaybeResult<T>>::Error>

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impl<T> Same for T

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type Output = T

Should always be Self
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impl<T> ToOwned for T
where T: Clone,

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

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type Error = Infallible

The type returned in the event of a conversion error.
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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 T
where U: TryFrom<T>,

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

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<I, T, U> Upcast<I, U> for T
where U: UpcastFrom<I, T>,

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fn upcast(self, interner: I) -> U

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impl<I, T> UpcastFrom<I, T> for T

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fn upcast_from(from: T, _tcx: I) -> T

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

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fn vzip(self) -> V

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impl<Tcx, T> Value<Tcx> for T
where Tcx: DepContext,

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default fn from_cycle_error( tcx: Tcx, cycle_error: &CycleError, _guar: ErrorGuaranteed, ) -> T

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impl<T> WithSubscriber for T

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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
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fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more
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impl<'a, T> Captures<'a> for T
where T: ?Sized,

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impl<'a, T> Captures<'a> for T
where T: ?Sized,

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impl<T> ErasedDestructor for T
where T: 'static,

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impl<T> MaybeSendSync for T

Layout§

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 64 bytes