- let mut compatible_variants = expected_adt.variants
- .iter()
- .filter(|variant| variant.fields.len() == 1)
- .filter_map(|variant| {
- let sole_field = &variant.fields[0];
- let sole_field_ty = sole_field.ty(self.tcx, substs);
- if self.can_coerce(expr_ty, sole_field_ty) {
- let variant_path = self.tcx.item_path_str(variant.did);
- Some(variant_path.trim_left_matches("std::prelude::v1::").to_string())
- } else {
- None
+ if expected_adt.is_enum() {
+ let mut compatible_variants = expected_adt.variants
+ .iter()
+ .filter(|variant| variant.fields.len() == 1)
+ .filter_map(|variant| {
+ let sole_field = &variant.fields[0];
+ let sole_field_ty = sole_field.ty(self.tcx, substs);
+ if self.can_coerce(expr_ty, sole_field_ty) {
+ let variant_path = self.tcx.item_path_str(variant.did);
+ Some(variant_path.trim_left_matches("std::prelude::v1::").to_string())
+ } else {
+ None
+ }
+ }).peekable();
+
+ if compatible_variants.peek().is_some() {
+ let expr_text = print::to_string(print::NO_ANN, |s| s.print_expr(expr));
+ let suggestions = compatible_variants
+ .map(|v| format!("{}({})", v, expr_text)).collect::<Vec<_>>();
+ err.span_suggestions_with_applicability(
+ expr.span,
+ "try using a variant of the expected type",
+ suggestions,
+ Applicability::MaybeIncorrect,
+ );