Struct rustc_typeck::bounds::Bounds

pub struct Bounds<'tcx> {
    pub region_bounds: Vec<(Binder<'tcx, Region<'tcx>>, Span)>,
    pub trait_bounds: Vec<(PolyTraitRef<'tcx>, Span, BoundConstness)>,
    pub projection_bounds: Vec<(PolyProjectionPredicate<'tcx>, Span)>,
    pub implicitly_sized: Option<Span>,
}

Collects together a list of type bounds. These lists of bounds occur in many places in Rust’s syntax:

trait Foo: Bar + Baz { }
           ^^^^^^^^^ supertrait list bounding the `Self` type parameter

fn foo<T: Bar + Baz>() { }
          ^^^^^^^^^ bounding the type parameter `T`

impl dyn Bar + Baz
         ^^^^^^^^^ bounding the forgotten dynamic type

Our representation is a bit mixed here – in some cases, we include the self type (e.g., trait_bounds) but in others we do not

Fields

region_bounds: Vec<(Binder<'tcx, Region<'tcx>>, Span)>

A list of region bounds on the (implicit) self type. So if you had T: 'a + 'b this might would be a list ['a, 'b] (but the T is not explicitly included).

trait_bounds: Vec<(PolyTraitRef<'tcx>, Span, BoundConstness)>

A list of trait bounds. So if you had T: Debug this would be T: Debug. Note that the self-type is explicit here.

projection_bounds: Vec<(PolyProjectionPredicate<'tcx>, Span)>

A list of projection equality bounds. So if you had T: Iterator<Item = u32> this would include <T as Iterator>::Item => u32. Note that the self-type is explicit here.

implicitly_sized: Option<Span>

Some if there is no ?Sized predicate. The span is the location in the source of the T declaration which can be cited as the source of the T: Sized requirement.

Implementations

impl<'tcx> Bounds<'tcx>

pub fn predicates<'out, 's>(
    &'s self,
    tcx: TyCtxt<'tcx>,
    param_ty: Ty<'tcx>
) -> impl Iterator<Item = (Predicate<'tcx>, Span)> + 'outwhere
    'tcx: 'out,
    's: 'out,

Converts a bounds list into a flat set of predicates (like where-clauses). Because some of our bounds listings (e.g., regions) don’t include the self-type, you must supply the self-type here (the param_ty parameter).

Trait Implementations

impl<'tcx> Clone for Bounds<'tcx>

fn clone(&self) -> Bounds<'tcx>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'tcx> Debug for Bounds<'tcx>

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

Formats the value using the given formatter.

impl<'tcx> Default for Bounds<'tcx>

fn default() -> Bounds<'tcx>

Returns the “default value” for a type.

impl<'tcx> PartialEq<Bounds<'tcx>> for Bounds<'tcx>

fn eq(&self, other: &Bounds<'tcx>) -> bool

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

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'tcx> Eq for Bounds<'tcx>

impl<'tcx> StructuralEq for Bounds<'tcx>

impl<'tcx> StructuralPartialEq for Bounds<'tcx>

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: 88 bytes