moving ifdefs into implementation

src/internal/platform_backend.h

@@ -114,9 +114,7 @@ namespace Blah
 		void gl_context_make_current(void* context);
 		void gl_context_destroy(void* context);
 
-#if _WIN32
 		// D3D11 Methods
 		void* d3d11_get_hwnd();
-#endif
 	}
 }

src/internal/platform_backend_sdl2.cpp

@@ -649,13 +649,16 @@ void PlatformBackend::gl_context_destroy(void* context)
 	SDL_GL_DeleteContext(context);
 }
 
-#if _WIN32
 void* PlatformBackend::d3d11_get_hwnd()
 {
+#if _WIN32
 	SDL_SysWMinfo info;
 	SDL_VERSION(&info.version);
 	SDL_GetWindowWMInfo(window, &info);
 	return info.info.win.window;
-}
+#else
+	return nullptr;
 #endif
+}
+
 #endif // BLAH_USE_SDL2