compile time check of window type and input type (TheCherno#190)

Adds Window::Create and Input::Create function into one place

Hazel/src/Hazel/Core/Input.cpp

@@ -0,0 +1,21 @@
+#include "hzpch.h"
+#include "Hazel/Core/Input.h"
+
+#ifdef HZ_PLATFORM_WINDOWS
+	#include "Platform/Windows/WindowsInput.h"
+#endif
+
+namespace Hazel {
+
+	Scope<Input> Input::s_Instance = Input::Create();
+
+	Scope<Input> Input::Create()
+	{
+	#ifdef HZ_PLATFORM_WINDOWS
+		return CreateScope<WindowsInput>();
+	#else
+		HZ_CORE_ASSERT(false, "Unknown platform!");
+		return nullptr;
+	#endif
+	}
+} 

Hazel/src/Hazel/Core/Input.h

@@ -20,6 +20,8 @@ namespace Hazel {
 		inline static std::pair<float, float> GetMousePosition() { return s_Instance->GetMousePositionImpl(); }
 		inline static float GetMouseX() { return s_Instance->GetMouseXImpl(); }
 		inline static float GetMouseY() { return s_Instance->GetMouseYImpl(); }
+
+		static Scope<Input> Create();
 	protected:
 		virtual bool IsKeyPressedImpl(KeyCode key) = 0;
 

Hazel/src/Hazel/Core/Window.cpp

@@ -0,0 +1,21 @@
+#include "hzpch.h"
+#include "Hazel/Core/Window.h"
+
+#ifdef HZ_PLATFORM_WINDOWS
+	#include "Platform/Windows/WindowsWindow.h"
+#endif
+
+namespace Hazel
+{
+
+	Scope<Window> Window::Create(const WindowProps& props)
+	{
+	#ifdef HZ_PLATFORM_WINDOWS
+		return CreateScope<WindowsWindow>(props);
+	#else
+		HZ_CORE_ASSERT(false, "Unknown platform!");
+		return nullptr;
+	#endif
+	}
+
+}

Hazel/src/Platform/Windows/WindowsInput.cpp

@@ -6,8 +6,6 @@
 
 namespace Hazel {
 
-	Scope<Input> Input::s_Instance = CreateScope<WindowsInput>();
-
 	bool WindowsInput::IsKeyPressedImpl(KeyCode key)
 	{
 		auto window = static_cast<GLFWwindow*>(Application::Get().GetWindow().GetNativeWindow());

Hazel/src/Platform/Windows/WindowsWindow.cpp

@@ -20,11 +20,6 @@ namespace Hazel {
 		HZ_CORE_ERROR("GLFW Error ({0}): {1}", error, description);
 	}
 
-	Scope<Window> Window::Create(const WindowProps& props)
-	{
-		return CreateScope<WindowsWindow>(props);
-	}
-
 	WindowsWindow::WindowsWindow(const WindowProps& props)
 	{
 		HZ_PROFILE_FUNCTION();