Trait rustc_middle::ty::TypeFolder
source · pub trait TypeFolder<I>: FallibleTypeFolder<I, Error = !>where
I: Interner,{
// Required method
fn interner(&self) -> I;
// Provided methods
fn fold_binder<T>(
&mut self,
t: <I as Interner>::Binder<T>
) -> <I as Interner>::Binder<T>
where T: TypeFoldable<I>,
<I as Interner>::Binder<T>: TypeSuperFoldable<I> { ... }
fn fold_ty(&mut self, t: <I as Interner>::Ty) -> <I as Interner>::Ty
where <I as Interner>::Ty: TypeSuperFoldable<I> { ... }
fn fold_region(
&mut self,
r: <I as Interner>::Region
) -> <I as Interner>::Region { ... }
fn fold_const(
&mut self,
c: <I as Interner>::Const
) -> <I as Interner>::Const
where <I as Interner>::Const: TypeSuperFoldable<I> { ... }
fn fold_predicate(
&mut self,
p: <I as Interner>::Predicate
) -> <I as Interner>::Predicate
where <I as Interner>::Predicate: TypeSuperFoldable<I> { ... }
}
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.