Trait rustc_middle::ty::fold::TypeFolder
source · pub trait TypeFolder<'tcx>: FallibleTypeFolder<'tcx, 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>,
{ ... }
fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> { ... }
fn fold_region(&mut self, r: Region<'tcx>) -> Region<'tcx> { ... }
fn fold_const(&mut self, c: Const<'tcx>) -> Const<'tcx> { ... }
fn fold_predicate(&mut self, p: Predicate<'tcx>) -> Predicate<'tcx> { ... }
}Expand description
This trait is implemented for every infallible 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.
A blanket implementation of FallibleTypeFolder will defer to
the infallible methods of this trait to ensure that the two APIs
are coherent.