commit e3da7da967b94f373c29a198ce45f30fb9f0e517
Author: Ed Catmur <ed@catmur.uk>
Date:   Tue Jan 31 16:27:04 2023 +0000

    Remove operator!= synthesized by spaceship
    
    An operator!= suppresses the reversed equality comparison candidate generation.
    
    This is visible in clang 16 (rc0 just released) and in gcc trunk (so probably gcc 13).

diff --git a/c++/src/kj/string.h b/c++/src/kj/string.h
index 193442aa..17835892 100644
--- a/c++/src/kj/string.h
+++ b/c++/src/kj/string.h
@@ -122,10 +122,14 @@ public:
   inline constexpr const char* end() const { return content.end() - 1; }
 
   inline constexpr bool operator==(decltype(nullptr)) const { return content.size() <= 1; }
+#if !__cpp_impl_three_way_comparison
   inline constexpr bool operator!=(decltype(nullptr)) const { return content.size() > 1; }
+#endif
 
   inline bool operator==(const StringPtr& other) const;
+#if !__cpp_impl_three_way_comparison
   inline bool operator!=(const StringPtr& other) const { return !(*this == other); }
+#endif
   inline bool operator< (const StringPtr& other) const;
   inline bool operator> (const StringPtr& other) const { return other < *this; }
   inline bool operator<=(const StringPtr& other) const { return !(other < *this); }