Three way comparison

morzhovets · Jan 2, 2024 · f4c595c · f4c595c
1 parent 6312478
commit f4c595c
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Showing 6 changed files with 48 additions and 1 deletion.
diff --git a/include/momo/MapUtility.h b/include/momo/MapUtility.h
@@ -123,7 +123,14 @@ namespace internal
 			return !pvIsEqual(pair1, ref2);
 		}
 
-		//? <, >, <=, >=
+#ifdef MOMO_HAS_THREE_WAY_COMPARISON
+		template<typename Pair2>
+		friend auto operator<=>(const MapReferenceStd& ref1, const Pair2& pair2)
+			requires requires { std::tie(ref1.first, ref1.second) <=> std::tie(pair2.first, pair2.second); }
+		{
+			return std::tie(ref1.first, ref1.second) <=> std::tie(pair2.first, pair2.second);
+		}
+#endif
 
 	protected:
 		explicit MapReferenceStd(MapReference mapRef) noexcept

diff --git a/include/momo/UserSettings.h b/include/momo/UserSettings.h
@@ -166,6 +166,11 @@
 #endif
 #endif
 
+#if defined(__cpp_impl_three_way_comparison) && defined(__cpp_lib_three_way_comparison) \
+	&& defined (__cpp_concepts)
+#define MOMO_HAS_THREE_WAY_COMPARISON
+#endif
+
 #ifdef __has_cpp_attribute
 #if __has_cpp_attribute(nodiscard)
 #define MOMO_NODISCARD [[nodiscard]]

diff --git a/include/momo/Utility.h b/include/momo/Utility.h
@@ -36,6 +36,10 @@
 #include <tuple>
 #include <initializer_list>
 
+#ifdef MOMO_HAS_THREE_WAY_COMPARISON
+#include <compare>
+#endif
+
 #define MOMO_FRIEND_SWAP(Object) \
 	friend void swap(Object& object1, Object& object2) \
 		noexcept(noexcept(object1.Swap(object2))) \

diff --git a/include/momo/stdish/map.h b/include/momo/stdish/map.h
@@ -660,6 +660,14 @@ namespace internal
 			return !(*this == right);
 		}
 
+#ifdef MOMO_HAS_THREE_WAY_COMPARISON
+		auto operator<=>(const map_base& right) const
+			requires requires (const_reference ref) { ref <=> ref; }
+		{
+			return std::lexicographical_compare_three_way(begin(), end(),
+				right.begin(), right.end());
+		}
+#else
 		bool operator<(const map_base& right) const
 		{
 			return std::lexicographical_compare(begin(), end(), right.begin(), right.end());
@@ -679,6 +687,7 @@ namespace internal
 		{
 			return right <= *this;
 		}
+#endif
 
 	protected:	//?
 		void ptAssign(std::initializer_list<value_type> values)

diff --git a/include/momo/stdish/set.h b/include/momo/stdish/set.h
@@ -554,6 +554,16 @@ class set
 		return !(*this == right);
 	}
 
+#ifdef MOMO_HAS_THREE_WAY_COMPARISON
+	auto operator<=>(const set& right) const
+		requires requires (const_reference ref) { std::tie(ref) <=> std::tie(ref); }
+	{
+		auto comp = [] (const value_type& value1, const value_type& value2)
+			{ return std::tie(value1) <=> std::tie(value2); };
+		return std::lexicographical_compare_three_way(begin(), end(),
+			right.begin(), right.end(), comp);
+	}
+#else
 	bool operator<(const set& right) const
 	{
 		return std::lexicographical_compare(begin(), end(), right.begin(), right.end());
@@ -573,6 +583,7 @@ class set
 	{
 		return right <= *this;
 	}
+#endif
 
 private:
 	static TreeSet pvCreateSet(set&& right, const allocator_type& alloc)

diff --git a/include/momo/stdish/vector.h b/include/momo/stdish/vector.h
@@ -463,6 +463,16 @@ class vector
 		return !(*this == right);
 	}
 
+#ifdef MOMO_HAS_THREE_WAY_COMPARISON
+	auto operator<=>(const vector& right) const
+		requires requires (const_reference ref) { std::tie(ref) <=> std::tie(ref); }
+	{
+		auto comp = [] (const value_type& value1, const value_type& value2)
+			{ return std::tie(value1) <=> std::tie(value2); };
+		return std::lexicographical_compare_three_way(begin(), end(),
+			right.begin(), right.end(), comp);
+	}
+#else
 	bool operator<(const vector& right) const
 	{
 		return std::lexicographical_compare(begin(), end(), right.begin(), right.end());
@@ -482,6 +492,7 @@ class vector
 	{
 		return right <= *this;
 	}
+#endif
 
 private:
 	static Array pvCreateArray(vector&& right, const allocator_type& alloc)