Struct rustc_middle::ty::visit::RegionVisitor

struct RegionVisitor<F> {
    outer_index: DebruijnIndex,
    callback: F,
}

Fields

outer_index: DebruijnIndex

The index of a binder just outside the things we have traversed. If we encounter a bound region bound by this binder or one outer to it, it appears free. Example:

      for<'a> fn(for<'b> fn(), T)
// ^          ^          ^     ^
// |          |          |     | here, would be shifted in 1
// |          |          | here, would be shifted in 2
// |          | here, would be `INNERMOST` shifted in by 1
// | here, initially, binder would be `INNERMOST`

You see that, initially, any bound value is free, because we’ve not traversed any binders. As we pass through a binder, we shift the outer_index by 1 to account for the new binder that encloses us.

callback: F

Trait Implementations

impl<'tcx, F> TypeVisitor<TyCtxt<'tcx>> for RegionVisitor<F>where F: FnMut(Region<'tcx>) -> bool,

type BreakTy = ()

fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>( &mut self, t: &Binder<'tcx, T> ) -> ControlFlow<Self::BreakTy>

fn visit_region(&mut self, r: Region<'tcx>) -> ControlFlow<Self::BreakTy>

fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<Self::BreakTy>

Layout

Note: Unable to compute type layout, possibly due to this type having generic parameters. Layout can only be computed for concrete, fully-instantiated types.