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

fn clone(&self) -> BlockTailInfo

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for BlockTailInfo

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

Formats the value using the given formatter.

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

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

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

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

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

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

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

type Lifted = Self

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

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

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

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

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

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

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.

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).

fn has_escaping_bound_vars(&self) -> bool

fn definitely_has_type_flags(&self, tcx: TyCtxt<'tcx>, flags: TypeFlags) -> bool

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

fn has_projections(&self) -> bool

fn has_opaque_types(&self) -> bool

fn references_error(&self) -> bool

fn potentially_has_param_types_or_consts(&self) -> bool

fn definitely_has_param_types_or_consts(&self, tcx: TyCtxt<'tcx>) -> bool

fn has_infer_regions(&self) -> bool

fn has_infer_types(&self) -> bool

fn has_infer_types_or_consts(&self) -> bool

fn needs_infer(&self) -> bool

fn has_placeholders(&self) -> bool

fn potentially_needs_subst(&self) -> bool

fn definitely_needs_subst(&self, tcx: TyCtxt<'tcx>) -> bool

fn has_free_regions(&self, tcx: TyCtxt<'tcx>) -> bool

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

fn has_erased_regions(&self) -> bool

fn has_erasable_regions(&self, tcx: TyCtxt<'tcx>) -> bool

True if there are any un-erased free regions.

fn is_known_global(&self) -> bool

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

fn is_global(&self, tcx: TyCtxt<'tcx>) -> 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.

fn has_late_bound_regions(&self) -> bool

True if there are any late-bound regions

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.

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: 12 bytes