pub enum ObligationCauseCode<'tcx> {
Show 58 variants MiscObligation, SliceOrArrayElem, TupleElem, ProjectionWf(AliasTy<'tcx>), ItemObligation(DefId), BindingObligation(DefIdSpan), ExprItemObligation(DefIdHirIdusize), ExprBindingObligation(DefIdSpanHirIdusize), ReferenceOutlivesReferent(Ty<'tcx>), ObjectTypeBound(Ty<'tcx>, Region<'tcx>), ObjectCastObligation(Ty<'tcx>, Ty<'tcx>), Coercion { source: Ty<'tcx>, target: Ty<'tcx>, }, AssignmentLhsSized, TupleInitializerSized, StructInitializerSized, VariableType(HirId), SizedArgumentType(Option<Span>), SizedReturnType, SizedYieldType, SizedBoxType, InlineAsmSized, RepeatElementCopy { is_const_fn: bool, }, FieldSized { adt_kind: AdtKind, span: Span, last: bool, }, ConstSized, SharedStatic, BuiltinDerivedObligation(DerivedObligationCause<'tcx>), ImplDerivedObligation(Box<ImplDerivedObligationCause<'tcx>>), DerivedObligation(DerivedObligationCause<'tcx>), FunctionArgumentObligation { arg_hir_id: HirId, call_hir_id: HirId, parent_code: InternedObligationCauseCode<'tcx>, }, CompareImplItemObligation { impl_item_def_id: LocalDefId, trait_item_def_id: DefId, kind: AssocKind, }, CheckAssociatedTypeBounds { impl_item_def_id: LocalDefId, trait_item_def_id: DefId, }, ExprAssignable, MatchExpressionArm(Box<MatchExpressionArmCause<'tcx>>), Pattern { span: Option<Span>, root_ty: Ty<'tcx>, origin_expr: bool, }, ConstPatternStructural, IfExpression(Box<IfExpressionCause<'tcx>>), IfExpressionWithNoElse, MainFunctionType, StartFunctionType, IntrinsicType, LetElse, MethodReceiver, UnifyReceiver(Box<UnifyReceiverContext<'tcx>>), ReturnNoExpression, ReturnValue(HirId), ReturnType, OpaqueReturnType(Option<(Ty<'tcx>, Span)>), BlockTailExpression(HirId), TrivialBound, OpaqueType, AwaitableExpr(Option<HirId>), ForLoopIterator, QuestionMark, WellFormed(Option<WellFormedLoc>), MatchImpl(ObligationCause<'tcx>, DefId), BinOp { rhs_span: Option<Span>, is_lit: bool, output_ty: Option<Ty<'tcx>>, }, AscribeUserTypeProvePredicate(Span), RustCall,
}

Variants§

§

MiscObligation

Not well classified or should be obvious from the span.

§

SliceOrArrayElem

A slice or array is WF only if T: Sized.

§

TupleElem

A tuple is WF only if its middle elements are Sized.

§

ProjectionWf(AliasTy<'tcx>)

This is the trait reference from the given projection.

§

ItemObligation(DefId)

Must satisfy all of the where-clause predicates of the given item.

§

BindingObligation(DefIdSpan)

Like ItemObligation, but carries the span of the predicate when it can be identified.

§

ExprItemObligation(DefIdHirIdusize)

Like ItemObligation, but carries the HirId of the expression that caused the obligation, and the usize indicates exactly which predicate it is in the list of instantiated predicates.

§

ExprBindingObligation(DefIdSpanHirIdusize)

Combines ExprItemObligation and BindingObligation.

§

ReferenceOutlivesReferent(Ty<'tcx>)

A type like &'a T is WF only if T: 'a.

§

ObjectTypeBound(Ty<'tcx>, Region<'tcx>)

A type like Box<Foo<'a> + 'b> is WF only if 'b: 'a.

§

ObjectCastObligation(Ty<'tcx>, Ty<'tcx>)

Obligation incurred due to an object cast.

§

Coercion

Fields

§source: Ty<'tcx>
§target: Ty<'tcx>

Obligation incurred due to a coercion.

§

AssignmentLhsSized

Various cases where expressions must be Sized / Copy / etc. L = X implies that L is Sized.

§

TupleInitializerSized

(x1, .., xn) must be Sized.

§

StructInitializerSized

S { ... } must be Sized.

§

VariableType(HirId)

Type of each variable must be Sized.

§

SizedArgumentType(Option<Span>)

Argument type must be Sized.

§

SizedReturnType

Return type must be Sized.

§

SizedYieldType

Yield type must be Sized.

§

SizedBoxType

Box expression result type must be Sized.

§

InlineAsmSized

Inline asm operand type must be Sized.

§

RepeatElementCopy

Fields

§is_const_fn: bool

If element is a const fn we display a help message suggesting to move the function call to a new const item while saying that T doesn’t implement Copy.

[expr; N] requires type_of(expr): Copy.

§

FieldSized

Fields

§adt_kind: AdtKind
§span: Span
§last: bool

Types of fields (other than the last, except for packed structs) in a struct must be sized.

§

ConstSized

Constant expressions must be sized.

§

SharedStatic

static items must have Sync type.

§

BuiltinDerivedObligation(DerivedObligationCause<'tcx>)

§

ImplDerivedObligation(Box<ImplDerivedObligationCause<'tcx>>)

§

DerivedObligation(DerivedObligationCause<'tcx>)

§

FunctionArgumentObligation

Fields

§arg_hir_id: HirId

The node of the relevant argument in the function call.

§call_hir_id: HirId

The node of the function call.

§parent_code: InternedObligationCauseCode<'tcx>

The obligation introduced by this argument.

§

CompareImplItemObligation

Fields

§impl_item_def_id: LocalDefId
§trait_item_def_id: DefId

Error derived when matching traits/impls; see ObligationCause for more details

§

CheckAssociatedTypeBounds

Fields

§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

§

ExprAssignable

Checking that this expression can be assigned to its target.

§

MatchExpressionArm(Box<MatchExpressionArmCause<'tcx>>)

Computing common supertype in the arms of a match expression

§

Pattern

Fields

§span: Option<Span>

The span of the scrutinee or type expression which caused the root_ty type.

§root_ty: Ty<'tcx>

The root expected type induced by a scrutinee or type expression.

§origin_expr: bool

Whether the Span came from an expression or a type expression.

Type error arising from type checking a pattern against an expected type.

§

ConstPatternStructural

Constants in patterns must have Structural type.

§

IfExpression(Box<IfExpressionCause<'tcx>>)

Computing common supertype in an if expression

§

IfExpressionWithNoElse

Computing common supertype of an if expression with no else counter-part

§

MainFunctionType

main has wrong type

§

StartFunctionType

start has wrong type

§

IntrinsicType

Intrinsic has wrong type

§

LetElse

A let else block does not diverge

§

MethodReceiver

Method receiver

§

UnifyReceiver(Box<UnifyReceiverContext<'tcx>>)

§

ReturnNoExpression

return with no expression

§

ReturnValue(HirId)

return with an expression

§

ReturnType

Return type of this function

§

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

Opaque return type of this function

§

BlockTailExpression(HirId)

Block implicit return

§

TrivialBound

#[feature(trivial_bounds)] is not enabled

§

OpaqueType

If X is the concrete type of an opaque type impl Y, then X must implement Y

§

AwaitableExpr(Option<HirId>)

§

ForLoopIterator

§

QuestionMark

§

WellFormed(Option<WellFormedLoc>)

Well-formed checking. If a WellFormedLoc is provided, then it will be used to perform HIR-based wf checking after an error occurs, in order to generate a more precise error span. This is purely for diagnostic purposes - it is always correct to use MiscObligation instead, or to specify WellFormed(None)

§

MatchImpl(ObligationCause<'tcx>, DefId)

From match_impl. The cause for us having to match an impl, and the DefId we are matching against.

§

BinOp

Fields

§rhs_span: Option<Span>
§is_lit: bool
§output_ty: Option<Ty<'tcx>>
§

AscribeUserTypeProvePredicate(Span)

§

RustCall

Implementations§

Returns the base obligation, ignoring derived obligations.

Trait Implementations§

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
Feeds this value into the given Hasher. Read more
Feeds a slice of this type into the given Hasher. Read more
This method tests for self and other values to be equal, and is used by ==. Read more
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.

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: 48 bytes

Size for each variant:

  • MiscObligation: 0 bytes
  • SliceOrArrayElem: 0 bytes
  • TupleElem: 0 bytes
  • ProjectionWf: 23 bytes
  • ItemObligation: 11 bytes
  • BindingObligation: 19 bytes
  • ExprItemObligation: 31 bytes
  • ExprBindingObligation: 39 bytes
  • ReferenceOutlivesReferent: 15 bytes
  • ObjectTypeBound: 23 bytes
  • ObjectCastObligation: 23 bytes
  • Coercion: 23 bytes
  • AssignmentLhsSized: 0 bytes
  • TupleInitializerSized: 0 bytes
  • StructInitializerSized: 0 bytes
  • VariableType: 11 bytes
  • SizedArgumentType: 15 bytes
  • SizedReturnType: 0 bytes
  • SizedYieldType: 0 bytes
  • SizedBoxType: 0 bytes
  • InlineAsmSized: 0 bytes
  • RepeatElementCopy: 1 byte
  • FieldSized: 11 bytes
  • ConstSized: 0 bytes
  • SharedStatic: 0 bytes
  • BuiltinDerivedObligation: 47 bytes
  • ImplDerivedObligation: 15 bytes
  • DerivedObligation: 47 bytes
  • FunctionArgumentObligation: 31 bytes
  • CompareImplItemObligation: 15 bytes
  • CheckAssociatedTypeBounds: 15 bytes
  • ExprAssignable: 0 bytes
  • MatchExpressionArm: 15 bytes
  • Pattern: 23 bytes
  • ConstPatternStructural: 0 bytes
  • IfExpression: 15 bytes
  • IfExpressionWithNoElse: 0 bytes
  • MainFunctionType: 0 bytes
  • StartFunctionType: 0 bytes
  • IntrinsicType: 0 bytes
  • LetElse: 0 bytes
  • MethodReceiver: 0 bytes
  • UnifyReceiver: 15 bytes
  • ReturnNoExpression: 0 bytes
  • ReturnValue: 11 bytes
  • ReturnType: 0 bytes
  • OpaqueReturnType: 23 bytes
  • BlockTailExpression: 11 bytes
  • TrivialBound: 0 bytes
  • OpaqueType: 0 bytes
  • AwaitableExpr: 11 bytes
  • ForLoopIterator: 0 bytes
  • QuestionMark: 0 bytes
  • WellFormed: 11 bytes
  • MatchImpl: 39 bytes
  • BinOp: 23 bytes
  • AscribeUserTypeProvePredicate: 11 bytes
  • RustCall: 0 bytes