Trait rustc_middle::ty::fold::TypeFolder
source · [−]pub trait TypeFolder<'tcx>: Sized {
type Error = !;
fn tcx<'a>(&'a self) -> TyCtxt<'tcx>;
fn fold_binder<T>(&mut self, t: Binder<'tcx, T>) -> Binder<'tcx, T>
where
T: TypeFoldable<'tcx>,
Self: TypeFolder<'tcx, Error = !>,
{ ... }
fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx>
where
Self: TypeFolder<'tcx, Error = !>,
{ ... }
fn fold_region(&mut self, r: Region<'tcx>) -> Region<'tcx>
where
Self: TypeFolder<'tcx, Error = !>,
{ ... }
fn fold_const(&mut self, c: Const<'tcx>) -> Const<'tcx>
where
Self: TypeFolder<'tcx, Error = !>,
{ ... }
fn fold_unevaluated(&mut self, uv: Unevaluated<'tcx>) -> Unevaluated<'tcx>
where
Self: TypeFolder<'tcx, Error = !>,
{ ... }
fn fold_predicate(&mut self, p: Predicate<'tcx>) -> Predicate<'tcx>
where
Self: TypeFolder<'tcx, Error = !>,
{ ... }
fn fold_mir_const(&mut self, c: ConstantKind<'tcx>) -> ConstantKind<'tcx>
where
Self: TypeFolder<'tcx, Error = !>,
{ ... }
}Expand description
This trait is implemented for every folding traversal. There is a fold
method defined for every type of interest. Each such method has a default
that does an “identity” fold. Implementations of these methods often fall
back to a super_fold_with method if the primary argument doesn’t
satisfy a particular condition.
If this folder is fallible (and therefore its Error
associated type is something other than the default !) then
FallibleTypeFolder should be implemented manually. Otherwise,
a blanket implementation of FallibleTypeFolder will defer to
the infallible methods of this trait to ensure that the two APIs
are coherent.