Trait rustc_middle::ty::fold::TypeFoldable

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pub trait TypeFoldable<'tcx>: Debug + Clone {

Show 24 methods    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(
        self, 
        folder: &mut F
    ) -> Result<Self, F::Error>;
    fn visit_with<V: TypeVisitor<'tcx>>(
        &self, 
        visitor: &mut V
    ) -> ControlFlow<V::BreakTy>;

    fn fold_with<F: TypeFolder<'tcx, Error = !>>(self, folder: &mut F) -> Self { ... }
    fn has_vars_bound_at_or_above(&self, binder: DebruijnIndex) -> bool { ... }
    fn has_vars_bound_above(&self, binder: DebruijnIndex) -> bool { ... }
    fn has_escaping_bound_vars(&self) -> bool { ... }
    fn has_type_flags(&self, flags: TypeFlags) -> bool { ... }
    fn has_projections(&self) -> bool { ... }
    fn has_opaque_types(&self) -> bool { ... }
    fn references_error(&self) -> bool { ... }
    fn error_reported(&self) -> Option<ErrorGuaranteed> { ... }
    fn has_param_types_or_consts(&self) -> bool { ... }
    fn has_infer_regions(&self) -> bool { ... }
    fn has_infer_types(&self) -> bool { ... }
    fn has_infer_types_or_consts(&self) -> bool { ... }
    fn needs_infer(&self) -> bool { ... }
    fn has_placeholders(&self) -> bool { ... }
    fn needs_subst(&self) -> bool { ... }
    fn has_free_regions(&self) -> bool { ... }
    fn has_erased_regions(&self) -> bool { ... }
    fn has_erasable_regions(&self) -> bool { ... }
    fn is_global(&self) -> bool { ... }
    fn has_late_bound_regions(&self) -> bool { ... }
    fn still_further_specializable(&self) -> bool { ... }

}
Expand description

This trait is implemented for every type that can be folded/visited, providing the skeleton of the traversal.

To implement this conveniently, use the derive macro located in rustc_macros.

Required Methods

The entry point for folding. To fold a value t with a folder f call: t.try_fold_with(f).

For most types, this just traverses the value, calling try_fold_with on each field/element.

For types of interest (such as Ty), the implementation of method calls a folder method specifically for that type (such as F::try_fold_ty). This is where control transfers from TypeFoldable to TypeFolder.

The entry point for visiting. To visit a value t with a visitor v call: t.visit_with(v).

For most types, this just traverses the value, calling visit_with on each field/element.

For types of interest (such as Ty), the implementation of this method that calls a visitor method specifically for that type (such as V::visit_ty). This is where control transfers from TypeFoldable to TypeVisitor.

Provided Methods

A convenient alternative to try_fold_with for use with infallible folders. Do not override this method, to ensure coherence with try_fold_with.

Returns true if self has any late-bound regions that are either bound by binder or bound by some binder outside of binder. If binder is ty::INNERMOST, this indicates whether there are any late-bound regions that appear free.

Returns true if this self has any regions that escape binder (and hence are not bound by it).

“Free” regions in this context means that it has any region that is not (a) erased or (b) late-bound.

True if there are any un-erased free regions.

Indicates whether this value references only ‘global’ generic parameters that are the same regardless of what fn we are in. This is used for caching.

True if there are any late-bound regions

Indicates whether this value still has parameters/placeholders/inference variables which could be replaced later, in a way that would change the results of impl specialization.

Implementations on Foreign Types

Implementors

AdtDefs are basically the same as a DefId.