Enum rustc_middle::traits::ObligationCauseCode [−][src]
pub enum ObligationCauseCode<'tcx> {
Show 50 variants
MiscObligation,
SliceOrArrayElem,
TupleElem,
ProjectionWf(ProjectionTy<'tcx>),
ItemObligation(DefId),
BindingObligation(DefId, Span),
ReferenceOutlivesReferent(Ty<'tcx>),
ObjectTypeBound(Ty<'tcx>, Region<'tcx>),
ObjectCastObligation(Ty<'tcx>),
Coercion {
source: Ty<'tcx>,
target: Ty<'tcx>,
},
AssignmentLhsSized,
TupleInitializerSized,
StructInitializerSized,
VariableType(HirId),
SizedArgumentType(Option<Span>),
SizedReturnType,
SizedYieldType,
SizedBoxType,
InlineAsmSized,
RepeatVec(bool),
FieldSized {
adt_kind: AdtKind,
span: Span,
last: bool,
},
ConstSized,
SharedStatic,
BuiltinDerivedObligation(DerivedObligationCause<'tcx>),
ImplDerivedObligation(DerivedObligationCause<'tcx>),
DerivedObligation(DerivedObligationCause<'tcx>),
FunctionArgumentObligation {
arg_hir_id: HirId,
call_hir_id: HirId,
parent_code: Lrc<ObligationCauseCode<'tcx>>,
},
CompareImplConstObligation,
CompareImplMethodObligation {
item_name: Symbol,
impl_item_def_id: DefId,
trait_item_def_id: DefId,
},
CompareImplTypeObligation {
item_name: Symbol,
impl_item_def_id: DefId,
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>),
IfExpressionWithNoElse,
MainFunctionType,
StartFunctionType,
IntrinsicType,
LetElse,
MethodReceiver,
UnifyReceiver(Box<UnifyReceiverContext<'tcx>>),
ReturnNoExpression,
ReturnValue(HirId),
ReturnType,
BlockTailExpression(HirId),
TrivialBound,
OpaqueType,
WellFormed(Option<WellFormedLoc>),
MatchImpl(ObligationCause<'tcx>, DefId),
}
Variants
Not well classified or should be obvious from the span.
A slice or array is WF only if T: Sized
.
A tuple is WF only if its middle elements are Sized
.
ProjectionWf(ProjectionTy<'tcx>)
This is the trait reference from the given projection.
Tuple Fields of ProjectionWf
0: ProjectionTy<'tcx>
ItemObligation(DefId)
In an impl of trait X
for type Y
, type Y
must
also implement all supertraits of X
.
Tuple Fields of ItemObligation
0: DefId
Like ItemObligation
, but with extra detail on the source of the obligation.
ReferenceOutlivesReferent(Ty<'tcx>)
A type like &'a T
is WF only if T: 'a
.
Tuple Fields of ReferenceOutlivesReferent
0: Ty<'tcx>
A type like Box<Foo<'a> + 'b>
is WF only if 'b: 'a
.
ObjectCastObligation(Ty<'tcx>)
Obligation incurred due to an object cast.
Tuple Fields of ObjectCastObligation
0: Ty<'tcx>
Obligation incurred due to a coercion.
Various cases where expressions must be Sized
/ Copy
/ etc.
L = X
implies that L
is Sized
.
(x1, .., xn)
must be Sized
.
S { ... }
must be Sized
.
VariableType(HirId)
Type of each variable must be Sized
.
Tuple Fields of VariableType
0: HirId
Argument type must be Sized
.
Return type must be Sized
.
Yield type must be Sized
.
Box expression result type must be Sized
.
Inline asm operand type must be Sized
.
RepeatVec(bool)
[T, ..n]
implies that T
must be Copy
.
If the function in the array repeat expression is a const fn
,
display a help message suggesting to move the function call to a
new const
item while saying that T
doesn’t implement Copy
.
Tuple Fields of RepeatVec
0: bool
Types of fields (other than the last, except for packed structs) in a struct must be sized.
Constant expressions must be sized.
static
items must have Sync
type.
BuiltinDerivedObligation(DerivedObligationCause<'tcx>)
Tuple Fields of BuiltinDerivedObligation
0: DerivedObligationCause<'tcx>
ImplDerivedObligation(DerivedObligationCause<'tcx>)
Tuple Fields of ImplDerivedObligation
0: DerivedObligationCause<'tcx>
DerivedObligation(DerivedObligationCause<'tcx>)
Tuple Fields of DerivedObligation
0: DerivedObligationCause<'tcx>
Fields of FunctionArgumentObligation
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: Lrc<ObligationCauseCode<'tcx>>
The obligation introduced by this argument.
Error derived when matching traits/impls; see ObligationCause for more details
Error derived when matching traits/impls; see ObligationCause for more details
Fields of CompareImplMethodObligation
Error derived when matching traits/impls; see ObligationCause for more details
Checking that this expression can be assigned where it needs to be
MatchExpressionArm(Box<MatchExpressionArmCause<'tcx>>)
Computing common supertype in the arms of a match expression
Tuple Fields of MatchExpressionArm
0: Box<MatchExpressionArmCause<'tcx>>
Type error arising from type checking a pattern against an expected type.
Fields of Pattern
Constants in patterns must have Structural
type.
IfExpression(Box<IfExpressionCause>)
Computing common supertype in an if expression
Tuple Fields of IfExpression
0: Box<IfExpressionCause>
Computing common supertype of an if expression with no else counter-part
main
has wrong type
start
has wrong type
Intrinsic has wrong type
A let else block does not diverge
Method receiver
UnifyReceiver(Box<UnifyReceiverContext<'tcx>>)
Tuple Fields of UnifyReceiver
0: Box<UnifyReceiverContext<'tcx>>
return
with no expression
ReturnValue(HirId)
return
with an expression
Tuple Fields of ReturnValue
0: HirId
Return type of this function
BlockTailExpression(HirId)
Block implicit return
Tuple Fields of BlockTailExpression
0: HirId
#[feature(trivial_bounds)] is not enabled
If X
is the concrete type of an opaque type impl Y
, then X
must implement Y
WellFormed(Option<WellFormedLoc>)
Well-formed checking. If a WellFormedLoc
is provided,
then it will be used to eprform 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)
Tuple Fields of WellFormed
0: Option<WellFormedLoc>
MatchImpl(ObligationCause<'tcx>, DefId)
From match_impl
. The cause for us having to match an impl, and the DefId we are matching against.
Tuple Fields of MatchImpl
0: ObligationCause<'tcx>
1: DefId
Implementations
Trait Implementations
type Lifted = ObligationCauseCode<'__lifted>
This method tests for self
and other
values to be equal, and is used
by ==
. Read more
This method tests for !=
.
Auto Trait Implementations
impl<'tcx> !RefUnwindSafe for ObligationCauseCode<'tcx>
impl<'tcx> !Send for ObligationCauseCode<'tcx>
impl<'tcx> !Sync for ObligationCauseCode<'tcx>
impl<'tcx> Unpin for ObligationCauseCode<'tcx>
impl<'tcx> !UnwindSafe for ObligationCauseCode<'tcx>
Blanket Implementations
Mutably borrows from an owned value. Read more
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: 40 bytes
Size for each variant:
MiscObligation
: 0 bytesSliceOrArrayElem
: 0 bytesTupleElem
: 0 bytesProjectionWf
: 23 bytesItemObligation
: 11 bytesBindingObligation
: 19 bytesReferenceOutlivesReferent
: 15 bytesObjectTypeBound
: 23 bytesObjectCastObligation
: 15 bytesCoercion
: 23 bytesAssignmentLhsSized
: 0 bytesTupleInitializerSized
: 0 bytesStructInitializerSized
: 0 bytesVariableType
: 11 bytesSizedArgumentType
: 15 bytesSizedReturnType
: 0 bytesSizedYieldType
: 0 bytesSizedBoxType
: 0 bytesInlineAsmSized
: 0 bytesRepeatVec
: 1 byteFieldSized
: 11 bytesConstSized
: 0 bytesSharedStatic
: 0 bytesBuiltinDerivedObligation
: 39 bytesImplDerivedObligation
: 39 bytesDerivedObligation
: 39 bytesFunctionArgumentObligation
: 31 bytesCompareImplConstObligation
: 0 bytesCompareImplMethodObligation
: 23 bytesCompareImplTypeObligation
: 23 bytesExprAssignable
: 0 bytesMatchExpressionArm
: 15 bytesPattern
: 23 bytesConstPatternStructural
: 0 bytesIfExpression
: 15 bytesIfExpressionWithNoElse
: 0 bytesMainFunctionType
: 0 bytesStartFunctionType
: 0 bytesIntrinsicType
: 0 bytesLetElse
: 0 bytesMethodReceiver
: 0 bytesUnifyReceiver
: 15 bytesReturnNoExpression
: 0 bytesReturnValue
: 11 bytesReturnType
: 0 bytesBlockTailExpression
: 11 bytesTrivialBound
: 0 bytesOpaqueType
: 0 bytesWellFormed
: 11 bytesMatchImpl
: 23 bytes