Enum rustc_middle::ty::adjustment::AllowTwoPhase

pub enum AllowTwoPhase {
    Yes,
    No,
}

At least for initial deployment, we want to limit two-phase borrows to only a few specific cases. Right now, those are mostly “things that desugar” into method calls:

• using x.some_method() syntax, where some_method takes &mut self,
• using Foo::some_method(&mut x, ...) syntax,
• binary assignment operators (+=, -=, *=, etc.). Anything else should be rejected until generalized two-phase borrow support is implemented. Right now, dataflow can’t handle the general case where there is more than one use of a mutable borrow, and we don’t want to accept too much new code via two-phase borrows, so we try to limit where we create two-phase capable mutable borrows. See #49434 for tracking.

Variants

Yes

No

Trait Implementations

impl Clone for AllowTwoPhase

fn clone(&self) -> AllowTwoPhase

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for AllowTwoPhase

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

Formats the value using the given formatter.

impl<'tcx, __D: TyDecoder<'tcx>> Decodable<__D> for AllowTwoPhase

fn decode(__decoder: &mut __D) -> Result<Self, <__D as Decoder>::Error>

impl<'tcx, __E: TyEncoder<'tcx>> Encodable<__E> for AllowTwoPhase

fn encode(&self, __encoder: &mut __E) -> Result<(), <__E as Encoder>::Error>

impl<'__ctx> HashStable<StableHashingContext<'__ctx>> for AllowTwoPhase

fn hash_stable(
    &self,
    __hcx: &mut StableHashingContext<'__ctx>,
    __hasher: &mut StableHasher
)

impl PartialEq<AllowTwoPhase> for AllowTwoPhase

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use]

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

This method tests for !=.

impl Copy for AllowTwoPhase

impl StructuralPartialEq for AllowTwoPhase