Removed custom scope guard and replaced it with TGuardValue defined in the engine.

Source/ImGui/Private/ImGuiContextManager.cpp

@@ -5,7 +5,6 @@
 #include "ImGuiDelegatesContainer.h"
 #include "ImGuiImplementation.h"
 #include "ImGuiModuleSettings.h"
-#include "Utilities/ScopeGuards.h"
 #include "Utilities/WorldContext.h"
 #include "Utilities/WorldContextIndex.h"
 

Source/ImGui/Private/Utilities/ScopeGuards.h

@@ -1,58 +0,0 @@
-// Distributed under the MIT License (MIT) (see accompanying LICENSE file)
-
-#pragma once
-
-namespace ScopeGuards
-{
-	// Saves snapshot of the object state and restores it during destruction.
-	template<typename T>
-	class TStateSaver
-	{
-	public:
-
-		// Constructor taking target object in state that we want to save.
-		TStateSaver(T& Target)
-			: Ptr(&Target)
-			, Value(Target)
-		{
-		}
-
-		// Move constructor allowing to transfer state out of scope.
-		TStateSaver(TStateSaver&& Other)
-			: Ptr(Other.Ptr)
-			, Value(MoveTemp(Other.Value))
-		{
-			// Release responsibility from the other object (std::exchange currently not supported by all platforms).
-			Other.Ptr = nullptr;
-		}
-
-		// Non-assignable to enforce acquisition on construction.
-		TStateSaver& operator=(TStateSaver&&) = delete;
-
-		// Non-copyable.
-		TStateSaver(const TStateSaver&) = delete;
-		TStateSaver& operator=(const TStateSaver&) = delete;
-
-		~TStateSaver()
-		{
-			if (Ptr)
-			{
-				*Ptr = Value;
-			}
-		}
-
-	private:
-
-		T* Ptr;
-		T Value;
-	};
-
-	// Create a state saver for target object. Unless saver is moved, state will be restored at the end of scope.
-	// @param Target - Target object in state that we want to save
-	// @returns State saver that unless moved, will restore target's state during scope exit
-	template<typename T>
-	TStateSaver<T> MakeStateSaver(T& Target)
-	{
-		return TStateSaver<T>{ Target };
-	}
-}

Source/ImGui/Private/Widgets/SImGuiWidget.cpp

@@ -12,7 +12,6 @@
 #include "ImGuiModuleSettings.h"
 #include "TextureManager.h"
 #include "Utilities/Arrays.h"
-#include "Utilities/ScopeGuards.h"
 #include "VersionCompatibility.h"
 
 #include <Engine/Console.h>
@@ -647,10 +646,6 @@ int32 SImGuiWidget::OnPaint(const FPaintArgs& Args, const FGeometry& AllottedGeo
 		{
 #if ENGINE_COMPATIBILITY_LEGACY_CLIPPING_API
 			DrawList.CopyVertexData(VertexBuffer, ImGuiToScreen, VertexClippingRect);
-
-			// Get access to the Slate scissor rectangle defined in Slate Core API, so we can customize elements drawing.
-			extern SLATECORE_API TOptional<FShortRect> GSlateScissorRect;
-			auto GSlateScissorRectSaver = ScopeGuards::MakeStateSaver(GSlateScissorRect);
 #else
 			DrawList.CopyVertexData(VertexBuffer, ImGuiToScreen);
 #endif // ENGINE_COMPATIBILITY_LEGACY_CLIPPING_API
@@ -672,7 +667,9 @@ int32 SImGuiWidget::OnPaint(const FPaintArgs& Args, const FGeometry& AllottedGeo
 				const FSlateRect ClippingRect = DrawCommand.ClippingRect.IntersectionWith(MyClippingRect);
 
 #if ENGINE_COMPATIBILITY_LEGACY_CLIPPING_API
-				GSlateScissorRect = FShortRect{ ClippingRect };
+				// Get access to the Slate scissor rectangle defined in Slate Core API, so we can customize elements drawing.
+				extern SLATECORE_API TOptional<FShortRect> GSlateScissorRect;
+				TGuardValue<TOptional<FShortRect>> GSlateScissorRecGuard(GSlateScissorRect, FShortRect{ ClippingRect });
 #else
 				OutDrawElements.PushClip(FSlateClippingZone{ ClippingRect });
 #endif // ENGINE_COMPATIBILITY_LEGACY_CLIPPING_API