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<__D: TyDecoder> Decodable<__D> for BlockTailInfo

fn decode(__decoder: &mut __D) -> Self

impl<__E: TyEncoder> Encodable<__E> for BlockTailInfo

fn encode(&self, __encoder: &mut __E)

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

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

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

fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>( self, _: &mut F ) -> Result<Self, F::Error>

The entry point for folding. To fold a value t with a folder f call: t.try_fold_with(f).

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

A convenient alternative to try_fold_with for use with infallible folders. Do not override this method, to ensure coherence with try_fold_with.

impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for BlockTailInfo

fn visit_with<F: TypeVisitor<TyCtxt<'tcx>>>(&self, _: &mut F) -> F::Result

The entry point for visiting. To visit a value t with a visitor v call: t.visit_with(v).

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