From 2b672289e17c18e140ba4f9b79cc5c873d3d5093 Mon Sep 17 00:00:00 2001
From: Jmgr <jmgr@jmgr.info>
Date: Sun, 25 Apr 2021 20:30:56 +0100
Subject: [PATCH] Fix optional being in experimental/ with some compilers

---
 CMakeLists.txt                      |  1 +
 Source/utils/paths.cpp              |  4 +++-
 Source/utils/stdcompat/optional.hpp | 14 ++++++++++++++
 3 files changed, 18 insertions(+), 1 deletion(-)
 create mode 100644 Source/utils/stdcompat/optional.hpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c0602ea6f..b7ba28bb1 100644
--- a/CMakeLists.txt
+++ b/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)
diff --git a/Source/utils/paths.cpp b/Source/utils/paths.cpp
index f8a1031f7..22f2196e3 100644
--- a/Source/utils/paths.cpp
+++ b/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
diff --git a/Source/utils/stdcompat/optional.hpp b/Source/utils/stdcompat/optional.hpp
new file mode 100644
index 000000000..cde1efc04
--- /dev/null
+++ b/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