Enum rustc_trait_selection::infer::SubregionOrigin

pub enum SubregionOrigin<'tcx> {
    Subtype(Box<TypeTrace<'tcx>, Global>),
    RelateObjectBound(Span),
    RelateParamBound(Span, Ty<'tcx>, Option<Span>),
    RelateRegionParamBound(Span),
    Reborrow(Span),
    ReferenceOutlivesReferent(Ty<'tcx>, Span),
    CompareImplItemObligation {
        span: Span,
        impl_item_def_id: LocalDefId,
        trait_item_def_id: DefId,
    },
    CheckAssociatedTypeBounds {
        parent: Box<SubregionOrigin<'tcx>, Global>,
        impl_item_def_id: LocalDefId,
        trait_item_def_id: DefId,
    },
    AscribeUserTypeProvePredicate(Span),
}

The origin of a r1 <= r2 constraint.

See error_reporting module for more details

Variants

Subtype(Box<TypeTrace<'tcx>, Global>)

Arose from a subtyping relation

RelateObjectBound(Span)

When casting &'a T to an &'b Trait object, relating 'a to 'b.

RelateParamBound(Span, Ty<'tcx>, Option<Span>)

Some type parameter was instantiated with the given type, and that type must outlive some region.

RelateRegionParamBound(Span)

The given region parameter was instantiated with a region that must outlive some other region.

Reborrow(Span)

Creating a pointer b to contents of another reference.

ReferenceOutlivesReferent(Ty<'tcx>, Span)

(&’a &’b T) where a >= b

CompareImplItemObligation

Fields

span: Span

impl_item_def_id: LocalDefId

trait_item_def_id: DefId

Comparing the signature and requirements of an impl method against the containing trait.

CheckAssociatedTypeBounds

Fields

parent: Box<SubregionOrigin<'tcx>, Global>

impl_item_def_id: LocalDefId

trait_item_def_id: DefId

Checking that the bounds of a trait’s associated type hold for a given impl.

AscribeUserTypeProvePredicate(Span)

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: 32 bytes

Size for each variant:

• Subtype: 12 bytes
• RelateObjectBound: 8 bytes
• RelateParamBound: 28 bytes
• RelateRegionParamBound: 8 bytes
• Reborrow: 8 bytes
• ReferenceOutlivesReferent: 20 bytes
• CompareImplItemObligation: 20 bytes
• CheckAssociatedTypeBounds: 20 bytes
• AscribeUserTypeProvePredicate: 8 bytes