pub enum Variance {
Covariant,
Invariant,
Contravariant,
Bivariant,
Unknown,
}Expand description
The variance of a lifetime or type parameter.
Variants§
Covariant
Invariant
Contravariant
Bivariant
Unknown
Variance was not sensible (e.g. on impls), not available (e.g. on higher-kinded predicates), or not computed (e.g. on parameters that Charon invents).
Trait Implementations§
Source§impl AstVisitable for Variance
impl AstVisitable for Variance
Source§fn drive<V: VisitAst>(&self, v: &mut V) -> ControlFlow<V::Break>
fn drive<V: VisitAst>(&self, v: &mut V) -> ControlFlow<V::Break>
Recursively visit this type with the provided visitor. This calls the visitor’s
visit_$any
method if it exists, otherwise visit_inner.Source§fn drive_mut<V: VisitAstMut>(&mut self, v: &mut V) -> ControlFlow<V::Break>
fn drive_mut<V: VisitAstMut>(&mut self, v: &mut V) -> ControlFlow<V::Break>
Recursively visit this type with the provided visitor. This calls the visitor’s
visit_$any
method if it exists, otherwise visit_inner.Source§fn drive_two<V: ZipAst>(&self, other: &Self, v: &mut V) -> ControlFlow<V::Break>
fn drive_two<V: ZipAst>(&self, other: &Self, v: &mut V) -> ControlFlow<V::Break>
Recursively visit this type with the provided visitor. This calls the visitor’s
visit_$any
method if it exists, otherwise visit_inner.Source§fn dyn_visit<T: AstVisitable>(&self, f: impl FnMut(&T))where
Self: Sized,
fn dyn_visit<T: AstVisitable>(&self, f: impl FnMut(&T))where
Self: Sized,
Visit all occurrences of that type inside
self, in pre-order traversal.Source§fn dyn_visit_mut<T: AstVisitable>(&mut self, f: impl FnMut(&mut T))where
Self: Sized,
fn dyn_visit_mut<T: AstVisitable>(&mut self, f: impl FnMut(&mut T))where
Self: Sized,
Visit all occurrences of that type inside
self, in pre-order traversal.Source§impl BodyVisitable for Variance
impl BodyVisitable for Variance
Source§fn drive_body<V: VisitBody>(&self, v: &mut V) -> ControlFlow<V::Break>
fn drive_body<V: VisitBody>(&self, v: &mut V) -> ControlFlow<V::Break>
Recursively visit this type with the provided visitor. This calls the visitor’s
visit_$any
method if it exists, otherwise visit_inner.Source§fn drive_body_mut<V: VisitBodyMut>(
&mut self,
v: &mut V,
) -> ControlFlow<V::Break>
fn drive_body_mut<V: VisitBodyMut>( &mut self, v: &mut V, ) -> ControlFlow<V::Break>
Recursively visit this type with the provided visitor. This calls the visitor’s
visit_$any
method if it exists, otherwise visit_inner.Source§fn dyn_visit_in_body<T: BodyVisitable>(&self, f: impl FnMut(&T))where
Self: Sized,
fn dyn_visit_in_body<T: BodyVisitable>(&self, f: impl FnMut(&T))where
Self: Sized,
Visit all occurrences of that type inside
self, in pre-order traversal.Source§fn dyn_visit_in_body_mut<T: BodyVisitable>(&mut self, f: impl FnMut(&mut T))where
Self: Sized,
fn dyn_visit_in_body_mut<T: BodyVisitable>(&mut self, f: impl FnMut(&mut T))where
Self: Sized,
Visit all occurrences of that type inside
self, in pre-order traversal.impl Copy for Variance
Source§impl<'de> Deserialize<'de> for Variance
impl<'de> Deserialize<'de> for Variance
Source§fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>where
__D: Deserializer<'de>,
fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>where
__D: Deserializer<'de>,
Deserialize this value from the given Serde deserializer. Read more
Source§impl<'s, V> Drive<'s, V> for Variancewhere
V: Visitor,
impl<'s, V> Drive<'s, V> for Variancewhere
V: Visitor,
Source§fn drive_inner(&'s self, visitor: &mut V) -> ControlFlow<V::Break>
fn drive_inner(&'s self, visitor: &mut V) -> ControlFlow<V::Break>
Call
v.visit() on the immediate contents of self.Source§impl<'s, V> DriveMut<'s, V> for Variancewhere
V: Visitor,
impl<'s, V> DriveMut<'s, V> for Variancewhere
V: Visitor,
Source§fn drive_inner_mut(&'s mut self, visitor: &mut V) -> ControlFlow<V::Break>
fn drive_inner_mut(&'s mut self, visitor: &mut V) -> ControlFlow<V::Break>
Call
v.visit() on the immediate contents of self.Source§impl<'s, V> DriveTwo<'s, V> for Variance
impl<'s, V> DriveTwo<'s, V> for Variance
Source§fn drive_two_inner(
&'s self,
other: &'s Self,
visitor: &mut V,
) -> ControlFlow<V::Break>
fn drive_two_inner( &'s self, other: &'s Self, visitor: &mut V, ) -> ControlFlow<V::Break>
Call
v.visit() on the immediate contents of self and other, if they correspond. If
the values don’t match up, this returns Break(Default::default()).impl Eq for Variance
Source§impl Ord for Variance
impl Ord for Variance
1.21.0 (const: unstable) · Source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
Compares and returns the maximum of two values. Read more
Source§impl PartialOrd for Variance
impl PartialOrd for Variance
impl StructuralPartialEq for Variance
Auto Trait Implementations§
impl Freeze for Variance
impl RefUnwindSafe for Variance
impl Send for Variance
impl Sync for Variance
impl Unpin for Variance
impl UnsafeUnpin for Variance
impl UnwindSafe for Variance
Blanket Implementations§
Source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
Source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
Source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
§impl<Q, K> Comparable<K> for Q
impl<Q, K> Comparable<K> for Q
impl<T> Dedup for T
impl<T> DeserializeOwned for Twhere
T: for<'de> Deserialize<'de>,
§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
Checks if this value is equivalent to the given key. Read more
§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
Compare self to
key and return true if they are equal.impl<T> HashConsable for T
§impl<T> Instrument for T
impl<T> Instrument for T
§fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
Source§impl<T> IntoEither for T
impl<T> IntoEither for T
Source§fn into_either(self, into_left: bool) -> Either<Self, Self> ⓘ
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 moreSource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self> ⓘ
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self> ⓘ
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 moreimpl<T> Mappable for T
impl<N> NodeTrait for N
Source§impl<T> TyVisitable for Twhere
T: AstVisitable,
impl<T> TyVisitable for Twhere
T: AstVisitable,
Source§fn visit_vars(&mut self, v: &mut impl VarsVisitor)
fn visit_vars(&mut self, v: &mut impl VarsVisitor)
Visit the variables contained in
self, as seen from the outside of self. This means
that any variable bound inside self will be skipped, and all the seen De Bruijn indices
will count from the outside of self.Source§fn substitute(self, generics: &GenericArgs) -> Self
fn substitute(self, generics: &GenericArgs) -> Self
Substitute the generic variables inside
self by replacing them with the provided values.
Note: if self is an item that comes from a TraitDecl, you must use
substitute_with_self or substitute_inner_binder, otherwise you’ll get panics.Source§fn substitute_inner_binder(self, generics: &GenericArgs) -> Self
fn substitute_inner_binder(self, generics: &GenericArgs) -> Self
Substitute the generic variables inside
self by replacing them with the provided values.
This is appropriate when substituting an inner binder.Source§fn substitute_explicits(self, generics: &GenericArgs) -> Self
fn substitute_explicits(self, generics: &GenericArgs) -> Self
Substitute only the type, region and const generic args.
Source§fn substitute_with_self(
self,
generics: &GenericArgs,
self_ref: &TraitRefKind,
) -> Self
fn substitute_with_self( self, generics: &GenericArgs, self_ref: &TraitRefKind, ) -> Self
Substitute the generic variables as well as the
TraitRefKind::SelfId trait ref.Source§fn substitute_with_tref(self, tref: &TraitRef) -> Self
fn substitute_with_tref(self, tref: &TraitRef) -> Self
Substitute the generic variables as well as the
TraitRefKind::SelfId trait ref.Source§fn try_substitute_with_tref(
self,
tref: &TraitRef,
) -> Result<Self, GenericsMismatch>
fn try_substitute_with_tref( self, tref: &TraitRef, ) -> Result<Self, GenericsMismatch>
Substitute the generic variables as well as the
TraitRefKind::SelfId trait ref.fn try_substitute( self, generics: &GenericArgs, ) -> Result<Self, GenericsMismatch>
fn try_substitute_with_self( self, generics: &GenericArgs, self_ref: &TraitRefKind, ) -> Result<Self, GenericsMismatch>
Source§fn move_under_binder(self) -> Self
fn move_under_binder(self) -> Self
Move under one binder.
Source§fn move_under_binders(self, depth: DeBruijnId) -> Self
fn move_under_binders(self, depth: DeBruijnId) -> Self
Move under
depth binders.Source§fn move_from_under_binder(self) -> Option<Self>
fn move_from_under_binder(self) -> Option<Self>
Move from under one binder.
Source§fn move_from_under_binders(self, depth: DeBruijnId) -> Option<Self>
fn move_from_under_binders(self, depth: DeBruijnId) -> Option<Self>
Move the value out of
depth binders. Returns None if it contains a variable bound in
one of these depth binders.Source§fn visit_db_id<B>(
&mut self,
f: impl FnMut(&mut DeBruijnId) -> ControlFlow<B>,
) -> ControlFlow<B>
fn visit_db_id<B>( &mut self, f: impl FnMut(&mut DeBruijnId) -> ControlFlow<B>, ) -> ControlFlow<B>
Visit the de Bruijn ids contained in
self, as seen from the outside of self. This means
that any variable bound inside self will be skipped, and all the seen indices will count
from the outside of self.Source§fn replace_erased_regions(self, f: impl FnMut() -> Region) -> Self
fn replace_erased_regions(self, f: impl FnMut() -> Region) -> Self
Replace all the erased regions by the output of the provided function. Binders levels are
handled automatically.