From 2cecf24712bfe0f3d821a6f3763156066c7c40ec Mon Sep 17 00:00:00 2001
From: Nikolay <211292+kolya7k@users.noreply.github.com>
Date: Mon, 30 Mar 2020 07:20:35 +0500
Subject: [PATCH 3/7] Three-way comparison for CLang 10 fix (#1679)

C++20 features must enable additional functionality, not to change interface completely
---
 include/rapidjson/document.h | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/include/rapidjson/document.h b/include/rapidjson/document.h
index 19f5a6a5..8e13d1cc 100644
--- a/include/rapidjson/document.h
+++ b/include/rapidjson/document.h
@@ -24,6 +24,9 @@
 #include "encodedstream.h"
 #include <new>      // placement new
 #include <limits>
+#ifdef __cpp_lib_three_way_comparison
+#include <compare>
+#endif
 
 RAPIDJSON_DIAG_PUSH
 #ifdef _MSC_VER
@@ -168,12 +171,16 @@ public:
 
     //! @name relations
     //@{
-    bool operator==(ConstIterator that) const { return ptr_ == that.ptr_; }
-    bool operator!=(ConstIterator that) const { return ptr_ != that.ptr_; }
-    bool operator<=(ConstIterator that) const { return ptr_ <= that.ptr_; }
-    bool operator>=(ConstIterator that) const { return ptr_ >= that.ptr_; }
-    bool operator< (ConstIterator that) const { return ptr_ < that.ptr_; }
-    bool operator> (ConstIterator that) const { return ptr_ > that.ptr_; }
+    template <bool Const_> bool operator==(const GenericMemberIterator<Const_, Encoding, Allocator>& that) const { return ptr_ == that.ptr_; }
+    template <bool Const_> bool operator!=(const GenericMemberIterator<Const_, Encoding, Allocator>& that) const { return ptr_ != that.ptr_; }
+    template <bool Const_> bool operator<=(const GenericMemberIterator<Const_, Encoding, Allocator>& that) const { return ptr_ <= that.ptr_; }
+    template <bool Const_> bool operator>=(const GenericMemberIterator<Const_, Encoding, Allocator>& that) const { return ptr_ >= that.ptr_; }
+    template <bool Const_> bool operator< (const GenericMemberIterator<Const_, Encoding, Allocator>& that) const { return ptr_ < that.ptr_; }
+    template <bool Const_> bool operator> (const GenericMemberIterator<Const_, Encoding, Allocator>& that) const { return ptr_ > that.ptr_; }
+
+#ifdef __cpp_lib_three_way_comparison
+    template <bool Const_> std::strong_ordering operator<=>(const GenericMemberIterator<Const_, Encoding, Allocator>& that) const { return ptr_ <=> that.ptr_; }
+#endif
     //@}
 
     //! @name dereference
-- 
2.43.0