Enum chalk_ir::Constraint

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pub enum Constraint<I: Interner> {
    LifetimeOutlives(Lifetime<I>, Lifetime<I>),
    TypeOutlives(Ty<I>, Lifetime<I>),
}
Expand description

A constraint on lifetimes.

When we search for solutions within the trait system, we essentially ignore lifetime constraints, instead gathering them up to return with our solution for later checking. This allows for decoupling between type and region checking in the compiler.

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LifetimeOutlives(Lifetime<I>, Lifetime<I>)

Outlives constraint 'a: 'b, indicating that the value of 'a must be a superset of the value of 'b.

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TypeOutlives(Ty<I>, Lifetime<I>)

Type outlives constraint T: 'a, indicating that the type T must live at least as long as the value of 'a.

Trait Implementations§

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impl<I: Interner> CastTo<Constraint<I>> for Constraint<I>

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fn cast_to( self, _interner: <Constraint<I> as HasInterner>::Interner, ) -> Constraint<I>

Cast a value to type T.
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impl<I: Clone + Interner> Clone for Constraint<I>

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fn clone(&self) -> Constraint<I>

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<I: Interner> Debug for Constraint<I>

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

Formats the value using the given formatter. Read more
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impl<I: Interner> HasInterner for Constraint<I>

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type Interner = I

The interner associated with the type.
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impl<I: Hash + Interner> Hash for Constraint<I>

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

Feeds this value into the given Hasher. Read more
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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<I: PartialEq + Interner> PartialEq for Constraint<I>

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fn eq(&self, other: &Constraint<I>) -> bool

This method tests for self and other values to be equal, and is used by ==.
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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.
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impl<I: Interner> TypeFoldable<I> for Constraint<I>

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fn try_fold_with<E>( self, folder: &mut dyn FallibleTypeFolder<I, Error = E>, outer_binder: DebruijnIndex, ) -> Result<Self, E>

Apply the given folder folder to self; binders is the number of binders that are in scope when beginning the folder. Typically binders starts as 0, but is adjusted when we encounter Binders<T> in the IR or other similar constructs.
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fn fold_with( self, folder: &mut dyn TypeFolder<I>, outer_binder: DebruijnIndex, ) -> Self

A convenient alternative to try_fold_with for use with infallible folders. Do not override this method, to ensure coherence with try_fold_with.
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impl<I: Interner> TypeVisitable<I> for Constraint<I>

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fn visit_with<B>( &self, visitor: &mut dyn TypeVisitor<I, BreakTy = B>, outer_binder: DebruijnIndex, ) -> ControlFlow<B>

Apply the given visitor visitor to self; binders is the number of binders that are in scope when beginning the visitor. Typically binders starts as 0, but is adjusted when we encounter Binders<T> in the IR or other similar constructs.
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impl<I: Interner> Zip<I> for Constraint<I>

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fn zip_with<Z: Zipper<I>>( zipper: &mut Z, variance: Variance, a: &Self, b: &Self, ) -> Fallible<()>

Uses the zipper to walk through two values, ensuring that they match.
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impl<I: Interner> Copy for Constraint<I>

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impl<I: Eq + Interner> Eq for Constraint<I>

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impl<I: Interner> StructuralPartialEq for Constraint<I>

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<T> Cast for T

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fn cast<U>(self, interner: U::Interner) -> U
where Self: CastTo<U>, U: HasInterner,

Cast a value to type U using CastTo.
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impl<T> CloneToUninit for T
where T: Copy,

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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> CloneToUninit for T
where T: Clone,

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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
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impl<T, I> CouldMatch<T> for T
where T: Zip<I> + HasInterner<Interner = I> + ?Sized, I: Interner,

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fn could_match( &self, interner: I, db: &dyn UnificationDatabase<I>, other: &T, ) -> bool

Checks whether self and other could possibly match.
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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, I> Shift<I> for T
where T: TypeFoldable<I>, I: Interner,

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fn shifted_in(self, interner: I) -> T

Shifts this term in one level of binders.
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fn shifted_in_from(self, interner: I, source_binder: DebruijnIndex) -> T

Shifts a term valid at outer_binder so that it is valid at the innermost binder. See DebruijnIndex::shifted_in_from for a detailed explanation.
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fn shifted_out_to( self, interner: I, target_binder: DebruijnIndex, ) -> Result<T, NoSolution>

Shifts a term valid at the innermost binder so that it is valid at outer_binder. See DebruijnIndex::shifted_out_to for a detailed explanation.
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fn shifted_out(self, interner: I) -> Result<T, NoSolution>

Shifts this term out one level of binders.
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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<T, I> VisitExt<I> for T
where I: Interner, T: TypeVisitable<I>,

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fn has_free_vars(&self, interner: I) -> bool

Check whether there are free (non-bound) variables.