Enum rustc_middle::mir::ConstraintCategory

pub enum ConstraintCategory {
    Return(ReturnConstraint),
    Yield,
    UseAsConst,
    UseAsStatic,
    TypeAnnotation,
    Cast,
    ClosureBounds,
    CallArgument,
    CopyBound,
    SizedBound,
    Assignment,
    OpaqueType,
    ClosureUpvar(HirId),
    Boring,
    BoringNoLocation,
    Internal,
}

Outlives-constraints can be categorized to determine whether and why they are interesting (for error reporting). Order of variants indicates sort order of the category, thereby influencing diagnostic output.

See also rustc_mir::borrow_check::constraints.

Variants

Return(ReturnConstraint)

Yield

UseAsConst

UseAsStatic

TypeAnnotation

Cast

ClosureBounds

A constraint that came from checking the body of a closure.

We try to get the category that the closure used when reporting this.

CallArgument

CopyBound

SizedBound

Assignment

OpaqueType

ClosureUpvar(HirId)

Boring

A "boring" constraint (caused by the given location) is one that the user probably doesn't want to see described in diagnostics, because it is kind of an artifact of the type system setup. Example: x = Foo { field: y } technically creates intermediate regions representing the "type of Foo { field: y }", and data flows from y into those variables, but they are not very interesting. The assignment into x on the other hand might be.

BoringNoLocation

Internal

A constraint that doesn't correspond to anything the user sees.

Trait Implementations

impl Clone for ConstraintCategory

fn clone(&self) -> ConstraintCategory

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for ConstraintCategory

impl Debug for ConstraintCategory

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'tcx, __D: TyDecoder<'tcx>> Decodable<__D> for ConstraintCategory

fn decode(__decoder: &mut __D) -> Result<Self, <__D as Decoder>::Error>

impl<'tcx, __E: TyEncoder<'tcx>> Encodable<__E> for ConstraintCategory

fn encode(&self, __encoder: &mut __E) -> Result<(), <__E as Encoder>::Error>

impl Eq for ConstraintCategory

impl Hash for ConstraintCategory

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given [Hasher].

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

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

impl Ord for ConstraintCategory

fn cmp(&self, other: &ConstraintCategory) -> Ordering

This method returns an [Ordering] between self and other.

#[must_use]fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]fn clamp(self, min: Self, max: Self) -> Self

🔬 This is a nightly-only experimental API. (clamp)

Restrict a value to a certain interval.

impl PartialEq<ConstraintCategory> for ConstraintCategory

fn eq(&self, other: &ConstraintCategory) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &ConstraintCategory) -> bool

This method tests for !=.

impl PartialOrd<ConstraintCategory> for ConstraintCategory

fn partial_cmp(&self, other: &ConstraintCategory) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &ConstraintCategory) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &ConstraintCategory) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &ConstraintCategory) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &ConstraintCategory) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralEq for ConstraintCategory

impl StructuralPartialEq for ConstraintCategory