1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
use rustc::hir;
use rustc::hir::itemlikevisit::ItemLikeVisitor;
use rustc::ty::TyCtxt;
pub fn test_variance<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
tcx.hir.krate().visit_all_item_likes(&mut VarianceTest { tcx });
}
struct VarianceTest<'a, 'tcx: 'a> {
tcx: TyCtxt<'a, 'tcx, 'tcx>
}
impl<'a, 'tcx> ItemLikeVisitor<'tcx> for VarianceTest<'a, 'tcx> {
fn visit_item(&mut self, item: &'tcx hir::Item) {
let item_def_id = self.tcx.hir.local_def_id(item.id);
if self.tcx.has_attr(item_def_id, "rustc_variance") {
let variances_of = self.tcx.variances_of(item_def_id);
span_err!(self.tcx.sess,
item.span,
E0208,
"{:?}",
variances_of);
}
}
fn visit_trait_item(&mut self, _: &'tcx hir::TraitItem) { }
fn visit_impl_item(&mut self, _: &'tcx hir::ImplItem) { }
}