Struct rustc_infer::traits::ObligationCause

pub struct ObligationCause<'tcx> {
    pub span: Span,
    pub body_id: LocalDefId,
    code: InternedObligationCauseCode<'tcx>,
}

The reason why we incurred this obligation; used for error reporting.

Non-misc ObligationCauseCodes are stored on the heap. This gives the best trade-off between keeping the type small (which makes copies cheaper) while not doing too many heap allocations.

We do not want to intern this as there are a lot of obligation causes which only live for a short period of time.

Fields

span: Span

body_id: LocalDefId

The ID of the fn body that triggered this obligation. This is used for region obligations to determine the precise environment in which the region obligation should be evaluated (in particular, closures can add new assumptions). See the field region_obligations of the FulfillmentContext for more information.

code: InternedObligationCauseCode<'tcx>

Trait Implementations

impl<'tcx> ObligationCauseExt<'tcx> for ObligationCause<'tcx>

fn as_failure_code(&self, terr: TypeError<'tcx>) -> FailureCode

fn as_failure_code_diag( &self, terr: TypeError<'tcx>, span: Span, subdiags: Vec<TypeErrorAdditionalDiags> ) -> ObligationCauseFailureCode

fn as_requirement_str(&self) -> &'static str

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: 24 bytes