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Certified

Enum Certified 

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#[non_exhaustive]
pub enum Certified { Certain { sign: Sign, precision: Precision, }, Uncertain { attempted: Precision, }, }
Expand description

A predicate evaluation that may or may not be trustworthy.

Uncertain is deliberately not a sign: it carries no Sign payload, so a caller cannot accidentally read a value out of it. The only way to obtain a Sign is to handle the uncertain case explicitly.

Variants (Non-exhaustive)§

This enum is marked as non-exhaustive
Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.
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Certain

The sign is proven at the reported precision.

Fields

§sign: Sign

The proven sign.

§precision: Precision

Precision tier at which the proof was obtained.

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Uncertain

The computed value was within its own error bound of zero, so the sign could not be determined at this precision. Escalate.

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§attempted: Precision

Precision tier that failed to decide.

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impl Certified

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pub fn from_filter( value: f64, error_bound: f64, precision: Precision, ) -> Certified

Certify a value against a filter’s absolute error bound.

The bound is the maximum absolute error the computation may carry. If zero lies inside value +- bound the sign is not decidable here, which is the whole point of a filtered predicate: it reports failure instead of guessing. A non-finite value or bound is never certifiable.

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pub const fn exact_sign(sign: Sign) -> Certified

Certify an exact computation. Only valid where no rounding occurred.

An exact zero is a certain answer – the configuration is genuinely degenerate – which is different from being unable to decide. A sign established by exact arithmetic, where no integer value exists.

An exact predicate cascade produces a proven sign without producing a representable magnitude: the determinant lives in a multi-term expansion, not one i64. Without this constructor such a result could only be reported as Uncertain, which would discard the very proof the exact path was paid for.

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pub const fn exact(value: i64) -> Certified

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pub const fn sign(self) -> Option<Sign>

The proven sign, or None when escalation is required.

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pub const fn is_certain(self) -> bool

Whether this result is safe to drive a topology decision.

Trait Implementations§

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impl Clone for Certified

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fn clone(&self) -> Certified

Returns a duplicate of the value. Read more
1.0.0 (const: unstable) · Source§

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

Performs copy-assignment from source. Read more
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impl Copy for Certified

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impl Debug for Certified

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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 Eq for Certified

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impl Hash for Certified

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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 PartialEq for Certified

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

Equality operator ==. Read more
1.0.0 (const: unstable) · Source§

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

Inequality operator !=. Read more
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impl StructuralPartialEq for Certified

Auto Trait Implementations§

Blanket Implementations§

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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> 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<ST, DT> CastableFrom<ST, Initialized, Initialized> for DT
where ST: ?Sized, DT: ?Sized,

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impl<ST, DT> CastableFrom<ST, Uninit, Uninit> for DT
where ST: ?Sized, DT: ?Sized,

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

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unsafe fn clone_to_uninit(&self, dest: *mut u8)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dest. 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, 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<T> Pointable for T

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const ALIGN: usize

The alignment of pointer.
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type Init = T

The type for initializers.
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unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
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unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
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unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
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unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
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impl<T> Read<Exclusive, BecauseExclusive> for T
where T: ?Sized,

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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.