## TypeVariableTable

# Struct TypeVariableTable

Source

    pub(crate) struct TypeVariableTable<'a, 'tcx> {
        storage: &'a mut TypeVariableStorage<'tcx>,
        undo_log: &'a mut InferCtxtUndoLogs<'tcx>,
    }

## Fields§

§`storage: &'a mut TypeVariableStorage<'tcx>`§`undo_log: &'a mut InferCtxtUndoLogs<'tcx>`

## Implementations§

Source§

### impl<'tcx> TypeVariableTable<'_, 'tcx>

Source

#### pub(crate) fn var_origin(&self, vid: TyVid) -> TypeVariableOrigin

Returns the origin that was given when `vid` was created.

Note that this function does not return care whether `vid` has been unified with something else or not.

Source

#### pub(crate) fn equate(&mut self, a: TyVid, b: TyVid)

Records that `a == b`.

Precondition: neither `a` nor `b` are known.

Source

#### pub(crate) fn sub_unify(&mut self, a: TyVid, b: TyVid)

Records that `a` and `b` are related via subtyping. We don’t track which of the two is the subtype.

Precondition: neither `a` nor `b` are known.

Source

#### pub(crate) fn instantiate(&mut self, vid: TyVid, ty: Ty<'tcx>)

Instantiates `vid` with the type `ty`.

Precondition: `vid` must not have been previously instantiated.

Source

#### pub(crate) fn new_var( &mut self, universe: UniverseIndex, origin: TypeVariableOrigin, ) -> TyVid

Creates a new type variable.

- `diverging`: indicates if this is a “diverging” type variable, e.g., one created as the type of a `return` expression. The code in this module doesn’t care if a variable is diverging, but the main Rust type-checker will sometimes “unify” such variables with the `!` or `()` types.
- `origin`: indicates why the type variable was created. The code in this module doesn’t care, but it can be useful for improving error messages.

Source

#### pub(crate) fn num_vars(&self) -> usize

Returns the number of type variables created thus far.

Source

#### pub(crate) fn root_var(&mut self, vid: TyVid) -> TyVid

Returns the “root” variable of `vid` in the `eq_relations` equivalence table. All type variables that have been equated will yield the same root variable (per the union-find algorithm), so `root_var(a) == root_var(b)` implies that `a == b` (transitively).

Source

#### pub(crate) fn sub_unification_table_root_var(&mut self, vid: TyVid) -> TyVid

Returns the “root” variable of `vid` in the `sub_unification_table` equivalence table. All type variables that have been are related via equality or subtyping will yield the same root variable (per the union-find algorithm), so `sub_unification_table_root_var(a) == sub_unification_table_root_var(b)` implies that:

    exists X. (a <: X || X <: a) && (b <: X || X <: b)

Source

#### pub(crate) fn probe(&mut self, vid: TyVid) -> TypeVariableValue<'tcx>

Retrieves the type to which `vid` has been instantiated, if any.

Source

#### pub(crate) fn inlined_probe(&mut self, vid: TyVid) -> TypeVariableValue<'tcx>

An always-inlined variant of `probe`, for very hot call sites.

Source

#### fn eq_relations( &mut self, ) -> UnificationTable<InPlace<TyVidEqKey<'tcx>, &'_ mut UnificationStorage<TyVidEqKey<'tcx>>, &'_ mut InferCtxtUndoLogs<'tcx>>>

Source

#### fn sub_unification_table( &mut self, ) -> UnificationTable<InPlace<TyVidSubKey, &'_ mut UnificationStorage<TyVidSubKey>, &'_ mut InferCtxtUndoLogs<'tcx>>>

Source

#### pub(crate) fn vars_since_snapshot( &mut self, value_count: usize, ) -> (Range<TyVid>, Vec<TypeVariableOrigin>)

Returns a range of the type variables created during the snapshot.

Source

#### pub(crate) fn unresolved_variables(&mut self) -> Vec<TyVid>

Returns indices of all variables that are not yet instantiated.

## Auto Trait Implementations§

§

### impl<'a, 'tcx> DynSend for TypeVariableTable<'a, 'tcx>

§

### impl<'a, 'tcx> DynSync for TypeVariableTable<'a, 'tcx>

§

### impl<'a, 'tcx> Freeze for TypeVariableTable<'a, 'tcx>

§

### impl<'a, 'tcx> !RefUnwindSafe for TypeVariableTable<'a, 'tcx>

§

### impl<'a, 'tcx> Send for TypeVariableTable<'a, 'tcx>

§

### impl<'a, 'tcx> Sync for TypeVariableTable<'a, 'tcx>

§

### impl<'a, 'tcx> Unpin for TypeVariableTable<'a, 'tcx>

§

### impl<'a, 'tcx> !UnwindSafe for TypeVariableTable<'a, 'tcx>

## Blanket Implementations§

Source§

### impl<T> Aligned for T

Source§

#### const ALIGN: Alignment

Alignment of `Self`.
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
Source§

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

Source§

#### 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<_>>())`.

Source§

#### type Output = R

Source§

### impl<T> From<T> for T

Source§

#### fn from(t: T) -> T

Returns the argument unchanged.

Source§

### impl<T> Instrument for T

Source§

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

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

#### 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
Source§

### impl<P> IntoQueryParam<P> for P

Source§

#### fn into_query_param(self) -> P

Source§

### impl<T> MaybeResult<T> for T

Source§

#### type Error = !

Source§

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

Source§

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

Source§

### impl<T> Pointable for T

Source§

#### const ALIGN: usize

The alignment of pointer.
Source§

#### type Init = T

The type for initializers.
Source§

#### unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
Source§

#### unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
Source§

#### unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
Source§

#### unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
Source§

### impl<T> Same for T

Source§

#### type Output = T

Should always be `Self`
Source§

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

Source§

#### 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>,

Source§

#### 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.
Source§

### impl<I, T, U> Upcast<I, U> for T
where U: UpcastFrom<I, T>,

Source§

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

Source§

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

Source§

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

Source§

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

Source§

#### fn vzip(self) -> V

Source§

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

Source§

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

Source§

### impl<T> WithSubscriber for T

Source§

#### 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
Source§

#### fn with_current_subscriber(self) -> WithDispatch<Self>

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

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

## 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: 16 bytes