syntax_data: {"ast_node_type":"function","tokens":[{"end":58,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
context_before: impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for ty::Const<'tcx> {
context_after:         self,