From f7e84233f42f4514e28a563ba8e8125a4362a9b4 Mon Sep 17 00:00:00 2001
From: Chuck Walbourn <chuckw@microsoft.com>
Date: Mon, 4 Apr 2022 23:23:06 -0700
Subject: [PATCH] Add C++20 spaceship operator to SimpleMath

---
 Inc/SimpleMath.h   | 17 +++++++++++++++--
 Inc/SimpleMath.inl |  2 ++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/Inc/SimpleMath.h b/Inc/SimpleMath.h
index 6ecd544..11c2b07 100644
--- a/Inc/SimpleMath.h
+++ b/Inc/SimpleMath.h
@@ -19,6 +19,10 @@
 #include <cstring>
 #include <functional>
 
+#if (__cplusplus >= 202002L)
+#include <compare>
+#endif
+
 #include <DirectXMath.h>
 #include <DirectXPackedVector.h>
 #include <DirectXCollision.h>
@@ -65,10 +69,14 @@ namespace DirectX
         #endif
 
             // Comparison operators
+        #if (__cplusplus >= 202002L)
+            bool operator == (const Rectangle&) const = default;
+            auto operator <=> (const Rectangle&) const = default;
+        #else
             bool operator == (const Rectangle& r) const noexcept { return (x == r.x) && (y == r.y) && (width == r.width) && (height == r.height); }
-            bool operator == (const RECT& rct) const noexcept { return (x == rct.left) && (y == rct.top) && (width == (rct.right - rct.left)) && (height == (rct.bottom - rct.top)); }
-
             bool operator != (const Rectangle& r) const noexcept { return (x != r.x) || (y != r.y) || (width != r.width) || (height != r.height); }
+        #endif
+            bool operator == (const RECT& rct) const noexcept { return (x == rct.left) && (y == rct.top) && (width == (rct.right - rct.left)) && (height == (rct.bottom - rct.top)); }
             bool operator != (const RECT& rct) const noexcept { return (x != rct.left) || (y != rct.top) || (width != (rct.right - rct.left)) || (height != (rct.bottom - rct.top)); }
 
             // Assignment operators
@@ -956,8 +964,13 @@ namespace DirectX
             Viewport& operator=(Viewport&&) = default;
 
             // Comparison operators
+        #if (__cplusplus >= 202002L)
+            bool operator == (const Viewport&) const = default;
+            auto operator <=> (const Viewport&) const = default;
+        #else
             bool operator == (const Viewport& vp) const noexcept;
             bool operator != (const Viewport& vp) const noexcept;
+        #endif
 
             // Assignment operators
             Viewport& operator= (const RECT& rct) noexcept;
diff --git a/Inc/SimpleMath.inl b/Inc/SimpleMath.inl
index e0242b2..2cd32dc 100644
--- a/Inc/SimpleMath.inl
+++ b/Inc/SimpleMath.inl
@@ -3724,6 +3724,7 @@ inline bool Ray::Intersects(const Plane& plane, _Out_ float& Dist) const noexcep
 // Comparision operators
 //------------------------------------------------------------------------------
 
+#if (__cplusplus < 202002L)
 inline bool Viewport::operator == (const Viewport& vp) const noexcept
 {
     return (x == vp.x && y == vp.y
@@ -3737,6 +3738,7 @@ inline bool Viewport::operator != (const Viewport& vp) const noexcept
         || width != vp.width || height != vp.height
         || minDepth != vp.minDepth || maxDepth != vp.maxDepth);
 }
+#endif
 
 //------------------------------------------------------------------------------
 // Assignment operators