From a30c2c26c08642dfb6b2c56121bea5ca45465c1b Mon Sep 17 00:00:00 2001
From: Ezra Shaw <ezrasure@outlook.com>
Date: Thu, 9 Mar 2023 20:42:45 +1300
Subject: feat: implement better error for manual impl of `Fn*` traits

---
 compiler/rustc_hir_analysis/src/errors.rs | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

(limited to 'compiler/rustc_hir_analysis/src/errors.rs')

diff --git a/compiler/rustc_hir_analysis/src/errors.rs b/compiler/rustc_hir_analysis/src/errors.rs
index 74fec93d91e..bf2cadddc0d 100644
--- a/compiler/rustc_hir_analysis/src/errors.rs
+++ b/compiler/rustc_hir_analysis/src/errors.rs
@@ -5,7 +5,7 @@ use rustc_errors::{
     error_code, Applicability, DiagnosticBuilder, ErrorGuaranteed, Handler, IntoDiagnostic,
     MultiSpan,
 };
-use rustc_macros::Diagnostic;
+use rustc_macros::{Diagnostic, Subdiagnostic};
 use rustc_middle::ty::Ty;
 use rustc_span::{symbol::Ident, Span, Symbol};
 
@@ -129,6 +129,18 @@ pub struct AssocTypeBindingNotAllowed {
     #[primary_span]
     #[label]
     pub span: Span,
+
+    #[subdiagnostic]
+    pub fn_trait_expansion: Option<ParenthesizedFnTraitExpansion>,
+}
+
+#[derive(Subdiagnostic)]
+#[help(hir_analysis_parenthesized_fn_trait_expansion)]
+pub struct ParenthesizedFnTraitExpansion {
+    #[primary_span]
+    pub span: Span,
+
+    pub expanded_type: String,
 }
 
 #[derive(Diagnostic)]
-- 
cgit 1.4.1-3-g733a5