Enum rustc_middle::mir::FakeBorrowKind
source · pub enum FakeBorrowKind {
Shallow,
Deep,
}
Variants§
Shallow
A shared shallow borrow. The immediately borrowed place must be immutable, but projections
from it don’t need to be. For example, a shallow borrow of a.b
doesn’t conflict with a
mutable borrow of a.b.c
.
This is used when lowering matches: when matching on a place we want to ensure that place have the same value from the start of the match until an arm is selected. This prevents this code from compiling:
let mut x = &Some(0);
match *x {
None => (),
Some(_) if { x = &None; false } => (),
Some(_) => (),
}
This can’t be a shared borrow because mutably borrowing (*x as Some).0
should not checking
the discriminant or accessing other variants, because the mutating (*x as Some).0
can’t
affect the discriminant of x
. E.g. the following is allowed:
let mut x = Some(0);
match x {
Some(_)
if {
if let Some(ref mut y) = x {
*y += 1;
};
true
} => {}
_ => {}
}
Deep
A shared (deep) borrow. Data must be immutable and is aliasable.
This is used when lowering deref patterns, where shallow borrows wouldn’t prevent something like:
Trait Implementations§
source§impl Clone for FakeBorrowKind
impl Clone for FakeBorrowKind
source§fn clone(&self) -> FakeBorrowKind
fn clone(&self) -> FakeBorrowKind
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for FakeBorrowKind
impl Debug for FakeBorrowKind
source§impl<__D: TyDecoder> Decodable<__D> for FakeBorrowKind
impl<__D: TyDecoder> Decodable<__D> for FakeBorrowKind
source§impl<__E: TyEncoder> Encodable<__E> for FakeBorrowKind
impl<__E: TyEncoder> Encodable<__E> for FakeBorrowKind
source§impl Hash for FakeBorrowKind
impl Hash for FakeBorrowKind
source§impl<'__ctx> HashStable<StableHashingContext<'__ctx>> for FakeBorrowKind
impl<'__ctx> HashStable<StableHashingContext<'__ctx>> for FakeBorrowKind
fn hash_stable( &self, __hcx: &mut StableHashingContext<'__ctx>, __hasher: &mut StableHasher, )
source§impl Ord for FakeBorrowKind
impl Ord for FakeBorrowKind
source§fn cmp(&self, other: &FakeBorrowKind) -> Ordering
fn cmp(&self, other: &FakeBorrowKind) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
source§impl PartialEq for FakeBorrowKind
impl PartialEq for FakeBorrowKind
source§fn eq(&self, other: &FakeBorrowKind) -> bool
fn eq(&self, other: &FakeBorrowKind) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for FakeBorrowKind
impl PartialOrd for FakeBorrowKind
source§fn partial_cmp(&self, other: &FakeBorrowKind) -> Option<Ordering>
fn partial_cmp(&self, other: &FakeBorrowKind) -> Option<Ordering>
1.0.0 · source§fn le(&self, other: &Rhs) -> bool
fn le(&self, other: &Rhs) -> bool
self
and other
) and is used by the <=
operator. Read moreimpl Copy for FakeBorrowKind
impl Eq for FakeBorrowKind
impl StructuralPartialEq for FakeBorrowKind
Auto Trait Implementations§
impl Freeze for FakeBorrowKind
impl RefUnwindSafe for FakeBorrowKind
impl Send for FakeBorrowKind
impl Sync for FakeBorrowKind
impl Unpin for FakeBorrowKind
impl UnwindSafe for FakeBorrowKind
Blanket Implementations§
source§impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for Twhere
T: Copy,
impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for Twhere
T: Copy,
fn allocate_on<'a>(self, arena: &'a Arena<'tcx>) -> &'a mut T
fn allocate_from_iter<'a>( arena: &'a Arena<'tcx>, iter: impl IntoIterator<Item = T>, ) -> &'a mut [T]
source§impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for Twhere
T: Copy,
impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for Twhere
T: Copy,
fn allocate_on<'a>(self, arena: &'a Arena<'tcx>) -> &'a mut T
fn allocate_from_iter<'a>( arena: &'a Arena<'tcx>, iter: impl IntoIterator<Item = T>, ) -> &'a mut [T]
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
source§impl<T> CloneToUninit for Twhere
T: Copy,
impl<T> CloneToUninit for Twhere
T: Copy,
source§unsafe fn clone_to_uninit(&self, dst: *mut T)
unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit
)source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§default unsafe fn clone_to_uninit(&self, dst: *mut T)
default unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit
)source§impl<T, R> CollectAndApply<T, R> for T
impl<T, R> CollectAndApply<T, R> for T
source§impl<Q, K> Comparable<K> for Q
impl<Q, K> Comparable<K> for Q
source§impl<Tcx, T> DepNodeParams<Tcx> for T
impl<Tcx, T> DepNodeParams<Tcx> for T
default fn fingerprint_style() -> FingerprintStyle
source§default fn to_fingerprint(&self, tcx: Tcx) -> Fingerprint
default fn to_fingerprint(&self, tcx: Tcx) -> Fingerprint
default fn to_debug_str(&self, _: Tcx) -> String
source§default fn recover(_: Tcx, _: &DepNode) -> Option<T>
default fn recover(_: Tcx, _: &DepNode) -> Option<T>
DepNode
,
something which is needed when forcing DepNode
s during red-green
evaluation. The query system will only call this method if
fingerprint_style()
is not FingerprintStyle::Opaque
.
It is always valid to return None
here, in which case incremental
compilation will treat the query as having changed instead of forcing it.source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.source§impl<T> Filterable for T
impl<T> Filterable for T
source§fn filterable(
self,
filter_name: &'static str,
) -> RequestFilterDataProvider<T, fn(_: DataRequest<'_>) -> bool>
fn filterable( self, filter_name: &'static str, ) -> RequestFilterDataProvider<T, fn(_: DataRequest<'_>) -> bool>
source§impl<T> Instrument for T
impl<T> Instrument for T
source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> 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>
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>
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 moresource§impl<P> IntoQueryParam<P> for P
impl<P> IntoQueryParam<P> for P
fn into_query_param(self) -> P
source§impl<T> MaybeResult<T> for T
impl<T> MaybeResult<T> for T
source§impl<I, T, U> Upcast<I, U> for Twhere
U: UpcastFrom<I, T>,
impl<I, T, U> Upcast<I, U> for Twhere
U: UpcastFrom<I, T>,
source§impl<I, T> UpcastFrom<I, T> for T
impl<I, T> UpcastFrom<I, T> for T
fn upcast_from(from: T, _tcx: I) -> T
source§impl<Tcx, T> Value<Tcx> for Twhere
Tcx: DepContext,
impl<Tcx, T> Value<Tcx> for Twhere
Tcx: DepContext,
default fn from_cycle_error( tcx: Tcx, cycle_error: &CycleError, _guar: ErrorGuaranteed, ) -> T
source§impl<T> WithSubscriber for T
impl<T> WithSubscriber for T
source§fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
source§fn with_current_subscriber(self) -> WithDispatch<Self>
fn with_current_subscriber(self) -> WithDispatch<Self>
impl<'a, T> Captures<'a> for Twhere
T: ?Sized,
impl<T> ErasedDestructor for Twhere
T: 'static,
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: 1 byte
Size for each variant:
Shallow
: 0 bytesDeep
: 0 bytes