1 files changed, 20 insertions, 7 deletions
diff --git a/libcxx/include/typeindex b/libcxx/include/typeindex
index 5fb7b30ecfee..e3132c8cb856 100644
--- a/libcxx/include/typeindex
+++ b/libcxx/include/typeindex
@@ -23,11 +23,12 @@ public:
     type_index(const type_info& rhs) noexcept;
 
     bool operator==(const type_index& rhs) const noexcept;
-    bool operator!=(const type_index& rhs) const noexcept;
+    bool operator!=(const type_index& rhs) const noexcept; // removed in C++20
     bool operator< (const type_index& rhs) const noexcept;
     bool operator<=(const type_index& rhs) const noexcept;
     bool operator> (const type_index& rhs) const noexcept;
     bool operator>=(const type_index& rhs) const noexcept;
+    strong_ordering operator<=>(const type_index& rhs) const noexcept; // C++20
 
     size_t hash_code() const noexcept;
     const char* name() const noexcept;
@@ -50,12 +51,6 @@ struct hash<type_index>
 #include <typeinfo>
 #include <version>
 
-#ifndef _LIBCPP_REMOVE_TRANSITIVE_INCLUDES
-#  include <iosfwd>
-#  include <new>
-#  include <utility>
-#endif
-
 // standard-mandated includes
 #include <compare>
 
@@ -76,8 +71,10 @@ public:
     bool operator==(const type_index& __y) const _NOEXCEPT
         {return *__t_ == *__y.__t_;}
     _LIBCPP_INLINE_VISIBILITY
+#if _LIBCPP_STD_VER <= 17
     bool operator!=(const type_index& __y) const _NOEXCEPT
         {return *__t_ != *__y.__t_;}
+#endif
     _LIBCPP_INLINE_VISIBILITY
     bool operator< (const type_index& __y) const _NOEXCEPT
         {return  __t_->before(*__y.__t_);}
@@ -90,6 +87,16 @@ public:
     _LIBCPP_INLINE_VISIBILITY
     bool operator>=(const type_index& __y) const _NOEXCEPT
         {return !__t_->before(*__y.__t_);}
+#if _LIBCPP_STD_VER > 17
+    _LIBCPP_HIDE_FROM_ABI
+    strong_ordering operator<=>(const type_index& __y) const noexcept {
+      if (*__t_ == *__y.__t_)
+        return strong_ordering::equal;
+      if (__t_->before(*__y.__t_))
+        return strong_ordering::less;
+      return strong_ordering::greater;
+    }
+#endif
 
     _LIBCPP_INLINE_VISIBILITY
     size_t hash_code() const _NOEXCEPT {return __t_->hash_code();}
@@ -110,4 +117,10 @@ struct _LIBCPP_TEMPLATE_VIS hash<type_index>
 
 _LIBCPP_END_NAMESPACE_STD
 
+#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
+#  include <iosfwd>
+#  include <new>
+#  include <utility>
+#endif
+
 #endif // _LIBCPP_TYPEINDEX