Struct rustc_middle::mir::BlockTailInfo

pub struct BlockTailInfo {
    pub tail_result_is_ignored: bool,
    pub span: Span,
}

BlockTailInfo is attached to the LocalDecl for temporaries created during evaluation of expressions in a block tail expression; that is, a block like { STMT_1; STMT_2; EXPR }.

It is used to improve diagnostics when such temporaries are involved in borrow_check errors, e.g., explanations of where the temporaries come from, when their destructors are run, and/or how one might revise the code to satisfy the borrow checker's rules.

Fields

tail_result_is_ignored: bool

If true, then the value resulting from evaluating this tail expression is ignored by the block's expression context.

Examples include { ...; tail }; and let _ = { ...; tail }; but not e.g., let _x = { ...; tail };

span: Span

Span of the tail expression.

Trait Implementations

impl Clone for BlockTailInfo

pub fn clone(&self) -> BlockTailInfo

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for BlockTailInfo

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

Formats the value using the given formatter.

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

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

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

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

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

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

impl<'tcx> Lift<'tcx> for BlockTailInfo

type Lifted = Self

pub fn lift_to_tcx(self, _: TyCtxt<'tcx>) -> Option<Self>

impl<'tcx> TypeFoldable<'tcx> for BlockTailInfo

pub fn super_fold_with<F: TypeFolder<'tcx>>(self, _: &mut F) -> BlockTailInfo

pub fn super_visit_with<F: TypeVisitor<'tcx>>(
    &self,
    _: &mut F
) -> ControlFlow<F::BreakTy>

pub fn fold_with<F: TypeFolder<'tcx>>(self, folder: &mut F) -> Self

pub fn visit_with<V: TypeVisitor<'tcx>>(
    &self,
    visitor: &mut V
) -> ControlFlow<V::BreakTy>

pub fn has_vars_bound_at_or_above(&self, binder: DebruijnIndex) -> bool

Returns true if self has any late-bound regions that are either bound by binder or bound by some binder outside of binder. If binder is ty::INNERMOST, this indicates whether there are any late-bound regions that appear free.

pub fn has_vars_bound_above(&self, binder: DebruijnIndex) -> bool

Returns true if this self has any regions that escape binder (and hence are not bound by it).

pub fn has_escaping_bound_vars(&self) -> bool

pub fn has_type_flags(&self, flags: TypeFlags) -> bool

pub fn has_projections(&self) -> bool

pub fn has_opaque_types(&self) -> bool

pub fn references_error(&self) -> bool

pub fn has_param_types_or_consts(&self) -> bool

pub fn has_infer_regions(&self) -> bool

pub fn has_infer_types(&self) -> bool

pub fn has_infer_types_or_consts(&self) -> bool

pub fn needs_infer(&self) -> bool

pub fn has_placeholders(&self) -> bool

pub fn needs_subst(&self) -> bool

pub fn has_free_regions(&self) -> bool

"Free" regions in this context means that it has any region that is not (a) erased or (b) late-bound.

pub fn has_erased_regions(&self) -> bool

pub fn has_erasable_regions(&self) -> bool

True if there are any un-erased free regions.

pub fn is_global(&self) -> bool

Indicates whether this value references only 'global' generic parameters that are the same regardless of what fn we are in. This is used for caching.

pub fn has_late_bound_regions(&self) -> bool

True if there are any late-bound regions

pub fn still_further_specializable(&self) -> bool

Indicates whether this value still has parameters/placeholders/inference variables which could be replaced later, in a way that would change the results of impl specialization.