Fix optional being in experimental/ with some compilers

CMakeLists.txt

@@ -706,6 +706,7 @@ endif()
 
 if(CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
   target_compile_options(${BIN_TARGET} PRIVATE "/W0")
+  target_compile_options(${BIN_TARGET} PRIVATE "/Zc:__cplusplus")
 endif()
 
 if(APPLE)

Source/utils/paths.cpp

@@ -1,8 +1,10 @@
 #include "utils/paths.h"
-#include "utils/log.hpp"
 
 #include <SDL.h>
 
+#include "utils/stdcompat/optional.hpp"
+#include "utils/log.hpp"
+
 #ifdef USE_SDL1
 #include "utils/sdl2_to_1_2_backports.h"
 #endif

Source/utils/stdcompat/optional.hpp

@@ -0,0 +1,14 @@
+#pragma once
+
+#ifdef __has_include
+#if defined(__cplusplus) && __cplusplus >= 201606L && __has_include(<optional>)
+#include <optional> // IWYU pragma: export
+#elif __has_include(<experimental/optional>)
+#include <experimental/optional> // IWYU pragma: export
+#define optional experimental::optional
+#else
+#error "Missing support for <optional> or <experimental/optional>"
+#endif
+#else
+#error "__has_include unavailable"
+#endif