1
Fork 0

Add note about wrapping in braces

Previously it was not clear why this errored or if it was even supported, as there was no
diagnostic that suggested wrapping it in braces.

Thus, add a simple diagnostic that suggests wrapping enum variants in braces.
This commit is contained in:
kadmin 2022-12-30 05:09:09 +00:00
parent 2c7536eaae
commit 077fae94a1
3 changed files with 70 additions and 10 deletions

View file

@ -1199,17 +1199,26 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
(_, _) => {
let got = if let Some(_) = term.ty() { "type" } else { "constant" };
let expected = def_kind.descr(assoc_item_def_id);
let reported = tcx
.sess
.struct_span_err(
let mut err = tcx.sess.struct_span_err(
binding.span,
&format!("expected {expected} bound, found {got}"),
);
err.span_note(
tcx.def_span(assoc_item_def_id),
&format!("{expected} defined here"),
);
if let hir::def::DefKind::AssocConst = def_kind
&& let Some(t) = term.ty() && (t.is_enum() || t.references_error())
&& tcx.features().associated_const_equality {
err.span_suggestion(
binding.span,
&format!("expected {expected} bound, found {got}"),
)
.span_note(
tcx.def_span(assoc_item_def_id),
&format!("{expected} defined here"),
)
.emit();
"if equating a const, try wrapping with braces",
format!("{} = {{ const }}", binding.item_name),
Applicability::HasPlaceholders,
);
}
let reported = err.emit();
term = match def_kind {
hir::def::DefKind::AssocTy => {
tcx.ty_error_with_guaranteed(reported).into()