{"ast_node_type":"other","tokens":[{"end":69,"kind":"keyword","start":0,"text":"///"}]}
    /// Converts a region inference variable into a `ty::Region` that
impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
    /// we can use for error reporting. If `r` is universally bound,