[c++20] Implement P1185R2 (as modified by P2002R0).

For each defaulted operator<=> in a class that doesn't explicitly
declare any operator==, also inject a matching implicit defaulted
operator==.

1 files changed, 4 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 344e54b7f3f..5b1394d7b34 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -9723,6 +9723,7 @@ enum OverloadCandidateKind {
   oc_implicit_move_constructor,
   oc_implicit_copy_assignment,
   oc_implicit_move_assignment,
+  oc_implicit_equality_comparison,
   oc_inherited_constructor
 };
 
@@ -9751,6 +9752,9 @@ ClassifyOverloadCandidate(Sema &S, NamedDecl *Found, FunctionDecl *Fn,
   }();
 
   OverloadCandidateKind Kind = [&]() {
+    if (Fn->isImplicit() && Fn->getOverloadedOperator() == OO_EqualEqual)
+      return oc_implicit_equality_comparison;
+
     if (CRK & CRK_Reversed)
       return oc_reversed_binary_operator;