Add: Optional implementation of std::optional for pre-C++17 compilers.

Sourced from https://github.com/akrzemi1/Optional, Boost Software License, Version 1.0.

8 files changed, 114 insertions, 80 deletions

diff --git a/projects/openttd_vs140.vcxproj b/projects/openttd_vs140.vcxproj
index 6453d62b8..4e7f7b7c8 100644
--- a/projects/openttd_vs140.vcxproj
+++ b/projects/openttd_vs140.vcxproj
@@ -974,6 +974,8 @@
     <ClInclude Include="..\src\table\water_land.h" />
     <ClCompile Include="..\src\3rdparty\md5\md5.cpp" />
     <ClInclude Include="..\src\3rdparty\md5\md5.h" />
+    <ClInclude Include="..\src\3rdparty\optional\optional.hpp" />
+    <ClInclude Include="..\src\3rdparty\optional\ottd_optional.h" />
     <ClCompile Include="..\src\script\script_config.cpp" />
     <ClInclude Include="..\src\script\script_config.hpp" />
     <ClInclude Include="..\src\script\script_fatalerror.hpp" />
diff --git a/projects/openttd_vs140.vcxproj.filters b/projects/openttd_vs140.vcxproj.filters
index 0405740d4..fd5c07157 100644
--- a/projects/openttd_vs140.vcxproj.filters
+++ b/projects/openttd_vs140.vcxproj.filters
@@ -28,78 +28,81 @@
     <Filter Include="MD5">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000008}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Script">
+    <Filter Include="Compat">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000009}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Squirrel">
+    <Filter Include="Script">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000010}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Squirrel headers">
+    <Filter Include="Squirrel">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000011}</UniqueIdentifier>
     </Filter>
-    <Filter Include="AI Core">
+    <Filter Include="Squirrel headers">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000012}</UniqueIdentifier>
     </Filter>
-    <Filter Include="AI API">
+    <Filter Include="AI Core">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000013}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Game API">
+    <Filter Include="AI API">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000014}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Game Core">
+    <Filter Include="Game API">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000015}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Script API">
+    <Filter Include="Game Core">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000016}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Script API Implementation">
+    <Filter Include="Script API">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000017}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Blitters">
+    <Filter Include="Script API Implementation">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000018}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Drivers">
+    <Filter Include="Blitters">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000019}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Sprite loaders">
+    <Filter Include="Drivers">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000020}</UniqueIdentifier>
     </Filter>
-    <Filter Include="NewGRF">
+    <Filter Include="Sprite loaders">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000021}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Map Accessors">
+    <Filter Include="NewGRF">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000022}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Misc">
+    <Filter Include="Map Accessors">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000023}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Network Core">
+    <Filter Include="Misc">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000024}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Pathfinder">
+    <Filter Include="Network Core">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000025}</UniqueIdentifier>
     </Filter>
-    <Filter Include="NPF">
+    <Filter Include="Pathfinder">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000026}</UniqueIdentifier>
     </Filter>
-    <Filter Include="YAPF">
+    <Filter Include="NPF">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000027}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Video">
+    <Filter Include="YAPF">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000028}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Music">
+    <Filter Include="Video">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000029}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Sound">
+    <Filter Include="Music">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000030}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Windows files">
+    <Filter Include="Sound">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000031}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Threading">
+    <Filter Include="Windows files">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000032}</UniqueIdentifier>
     </Filter>
+    <Filter Include="Threading">
+      <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000033}</UniqueIdentifier>
+    </Filter>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\src\airport.cpp">
@@ -2010,6 +2013,12 @@
     <ClInclude Include="..\src\3rdparty\md5\md5.h">
       <Filter>MD5</Filter>
     </ClInclude>
+    <ClInclude Include="..\src\3rdparty\optional\optional.hpp">
+      <Filter>Compat</Filter>
+    </ClInclude>
+    <ClInclude Include="..\src\3rdparty\optional\ottd_optional.h">
+      <Filter>Compat</Filter>
+    </ClInclude>
     <ClCompile Include="..\src\script\script_config.cpp">
       <Filter>Script</Filter>
     </ClCompile>
diff --git a/projects/openttd_vs141.vcxproj b/projects/openttd_vs141.vcxproj
index ecfed4a03..4ab1ad85d 100644
--- a/projects/openttd_vs141.vcxproj
+++ b/projects/openttd_vs141.vcxproj
@@ -974,6 +974,8 @@
     <ClInclude Include="..\src\table\water_land.h" />
     <ClCompile Include="..\src\3rdparty\md5\md5.cpp" />
     <ClInclude Include="..\src\3rdparty\md5\md5.h" />
+    <ClInclude Include="..\src\3rdparty\optional\optional.hpp" />
+    <ClInclude Include="..\src\3rdparty\optional\ottd_optional.h" />
     <ClCompile Include="..\src\script\script_config.cpp" />
     <ClInclude Include="..\src\script\script_config.hpp" />
     <ClInclude Include="..\src\script\script_fatalerror.hpp" />
diff --git a/projects/openttd_vs141.vcxproj.filters b/projects/openttd_vs141.vcxproj.filters
index 0405740d4..fd5c07157 100644
--- a/projects/openttd_vs141.vcxproj.filters
+++ b/projects/openttd_vs141.vcxproj.filters
@@ -28,78 +28,81 @@
     <Filter Include="MD5">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000008}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Script">
+    <Filter Include="Compat">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000009}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Squirrel">
+    <Filter Include="Script">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000010}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Squirrel headers">
+    <Filter Include="Squirrel">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000011}</UniqueIdentifier>
     </Filter>
-    <Filter Include="AI Core">
+    <Filter Include="Squirrel headers">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000012}</UniqueIdentifier>
     </Filter>
-    <Filter Include="AI API">
+    <Filter Include="AI Core">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000013}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Game API">
+    <Filter Include="AI API">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000014}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Game Core">
+    <Filter Include="Game API">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000015}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Script API">
+    <Filter Include="Game Core">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000016}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Script API Implementation">
+    <Filter Include="Script API">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000017}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Blitters">
+    <Filter Include="Script API Implementation">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000018}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Drivers">
+    <Filter Include="Blitters">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000019}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Sprite loaders">
+    <Filter Include="Drivers">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000020}</UniqueIdentifier>
     </Filter>
-    <Filter Include="NewGRF">
+    <Filter Include="Sprite loaders">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000021}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Map Accessors">
+    <Filter Include="NewGRF">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000022}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Misc">
+    <Filter Include="Map Accessors">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000023}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Network Core">
+    <Filter Include="Misc">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000024}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Pathfinder">
+    <Filter Include="Network Core">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000025}</UniqueIdentifier>
     </Filter>
-    <Filter Include="NPF">
+    <Filter Include="Pathfinder">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000026}</UniqueIdentifier>
     </Filter>
-    <Filter Include="YAPF">
+    <Filter Include="NPF">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000027}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Video">
+    <Filter Include="YAPF">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000028}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Music">
+    <Filter Include="Video">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000029}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Sound">
+    <Filter Include="Music">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000030}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Windows files">
+    <Filter Include="Sound">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000031}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Threading">
+    <Filter Include="Windows files">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000032}</UniqueIdentifier>
     </Filter>
+    <Filter Include="Threading">
+      <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000033}</UniqueIdentifier>
+    </Filter>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\src\airport.cpp">
@@ -2010,6 +2013,12 @@
     <ClInclude Include="..\src\3rdparty\md5\md5.h">
       <Filter>MD5</Filter>
     </ClInclude>
+    <ClInclude Include="..\src\3rdparty\optional\optional.hpp">
+      <Filter>Compat</Filter>
+    </ClInclude>
+    <ClInclude Include="..\src\3rdparty\optional\ottd_optional.h">
+      <Filter>Compat</Filter>
+    </ClInclude>
     <ClCompile Include="..\src\script\script_config.cpp">
       <Filter>Script</Filter>
     </ClCompile>
diff --git a/projects/openttd_vs142.vcxproj b/projects/openttd_vs142.vcxproj
index 49858a3e1..2539fe1d5 100644
--- a/projects/openttd_vs142.vcxproj
+++ b/projects/openttd_vs142.vcxproj
@@ -100,7 +100,7 @@
       </HeaderFileName>
     </Midl>
     <ClCompile>
-      <AdditionalOptions>/J /Zc:throwingNew /std:c++latest %(AdditionalOptions)</AdditionalOptions>
+      <AdditionalOptions>/J /Zc:throwingNew /std:c++latest /Zc:__cplusplus %(AdditionalOptions)</AdditionalOptions>
       <Optimization>Full</Optimization>
       <InlineFunctionExpansion>AnySuitable</InlineFunctionExpansion>
       <IntrinsicFunctions>true</IntrinsicFunctions>
@@ -168,7 +168,7 @@
       </HeaderFileName>
     </Midl>
     <ClCompile>
-      <AdditionalOptions>/J /Zc:throwingNew /std:c++latest %(AdditionalOptions)</AdditionalOptions>
+      <AdditionalOptions>/J /Zc:throwingNew /std:c++latest /Zc:__cplusplus %(AdditionalOptions)</AdditionalOptions>
       <Optimization>Disabled</Optimization>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <AdditionalIncludeDirectories>..\objs\langs;..\objs\settings;..\src\3rdparty\squirrel\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
@@ -223,7 +223,7 @@
       </HeaderFileName>
     </Midl>
     <ClCompile>
-      <AdditionalOptions>/J /Zc:throwingNew /std:c++latest %(AdditionalOptions)</AdditionalOptions>
+      <AdditionalOptions>/J /Zc:throwingNew /std:c++latest /Zc:__cplusplus %(AdditionalOptions)</AdditionalOptions>
       <Optimization>Full</Optimization>
       <InlineFunctionExpansion>AnySuitable</InlineFunctionExpansion>
       <IntrinsicFunctions>true</IntrinsicFunctions>
@@ -289,7 +289,7 @@
       </HeaderFileName>
     </Midl>
     <ClCompile>
-      <AdditionalOptions>/J /Zc:throwingNew /std:c++latest %(AdditionalOptions)</AdditionalOptions>
+      <AdditionalOptions>/J /Zc:throwingNew /std:c++latest /Zc:__cplusplus %(AdditionalOptions)</AdditionalOptions>
       <Optimization>Disabled</Optimization>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <AdditionalIncludeDirectories>..\objs\langs;..\objs\settings;..\src\3rdparty\squirrel\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
@@ -974,6 +974,8 @@
     <ClInclude Include="..\src\table\water_land.h" />
     <ClCompile Include="..\src\3rdparty\md5\md5.cpp" />
     <ClInclude Include="..\src\3rdparty\md5\md5.h" />
+    <ClInclude Include="..\src\3rdparty\optional\optional.hpp" />
+    <ClInclude Include="..\src\3rdparty\optional\ottd_optional.h" />
     <ClCompile Include="..\src\script\script_config.cpp" />
     <ClInclude Include="..\src\script\script_config.hpp" />
     <ClInclude Include="..\src\script\script_fatalerror.hpp" />
diff --git a/projects/openttd_vs142.vcxproj.filters b/projects/openttd_vs142.vcxproj.filters
index 0405740d4..fd5c07157 100644
--- a/projects/openttd_vs142.vcxproj.filters
+++ b/projects/openttd_vs142.vcxproj.filters
@@ -28,78 +28,81 @@
     <Filter Include="MD5">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000008}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Script">
+    <Filter Include="Compat">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000009}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Squirrel">
+    <Filter Include="Script">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000010}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Squirrel headers">
+    <Filter Include="Squirrel">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000011}</UniqueIdentifier>
     </Filter>
-    <Filter Include="AI Core">
+    <Filter Include="Squirrel headers">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000012}</UniqueIdentifier>
     </Filter>
-    <Filter Include="AI API">
+    <Filter Include="AI Core">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000013}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Game API">
+    <Filter Include="AI API">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000014}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Game Core">
+    <Filter Include="Game API">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000015}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Script API">
+    <Filter Include="Game Core">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000016}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Script API Implementation">
+    <Filter Include="Script API">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000017}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Blitters">
+    <Filter Include="Script API Implementation">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000018}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Drivers">
+    <Filter Include="Blitters">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000019}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Sprite loaders">
+    <Filter Include="Drivers">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000020}</UniqueIdentifier>
     </Filter>
-    <Filter Include="NewGRF">
+    <Filter Include="Sprite loaders">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000021}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Map Accessors">
+    <Filter Include="NewGRF">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000022}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Misc">
+    <Filter Include="Map Accessors">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000023}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Network Core">
+    <Filter Include="Misc">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000024}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Pathfinder">
+    <Filter Include="Network Core">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000025}</UniqueIdentifier>
     </Filter>
-    <Filter Include="NPF">
+    <Filter Include="Pathfinder">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000026}</UniqueIdentifier>
     </Filter>
-    <Filter Include="YAPF">
+    <Filter Include="NPF">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000027}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Video">
+    <Filter Include="YAPF">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000028}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Music">
+    <Filter Include="Video">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000029}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Sound">
+    <Filter Include="Music">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000030}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Windows files">
+    <Filter Include="Sound">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000031}</UniqueIdentifier>
     </Filter>
-    <Filter Include="Threading">
+    <Filter Include="Windows files">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000032}</UniqueIdentifier>
     </Filter>
+    <Filter Include="Threading">
+      <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000033}</UniqueIdentifier>
+    </Filter>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\src\airport.cpp">
@@ -2010,6 +2013,12 @@
     <ClInclude Include="..\src\3rdparty\md5\md5.h">
       <Filter>MD5</Filter>
     </ClInclude>
+    <ClInclude Include="..\src\3rdparty\optional\optional.hpp">
+      <Filter>Compat</Filter>
+    </ClInclude>
+    <ClInclude Include="..\src\3rdparty\optional\ottd_optional.h">
+      <Filter>Compat</Filter>
+    </ClInclude>
     <ClCompile Include="..\src\script\script_config.cpp">
       <Filter>Script</Filter>
     </ClCompile>
diff --git a/projects/openttd_vs142.vcxproj.in b/projects/openttd_vs142.vcxproj.in
index 83befcd8d..6941b3450 100644
--- a/projects/openttd_vs142.vcxproj.in
+++ b/projects/openttd_vs142.vcxproj.in
@@ -100,7 +100,7 @@
       </HeaderFileName>
     </Midl>
     <ClCompile>
-      <AdditionalOptions>/J /Zc:throwingNew /std:c++latest %(AdditionalOptions)</AdditionalOptions>
+      <AdditionalOptions>/J /Zc:throwingNew /std:c++latest /Zc:__cplusplus %(AdditionalOptions)</AdditionalOptions>
       <Optimization>Full</Optimization>
       <InlineFunctionExpansion>AnySuitable</InlineFunctionExpansion>
       <IntrinsicFunctions>true</IntrinsicFunctions>
@@ -168,7 +168,7 @@
       </HeaderFileName>
     </Midl>
     <ClCompile>
-      <AdditionalOptions>/J /Zc:throwingNew /std:c++latest %(AdditionalOptions)</AdditionalOptions>
+      <AdditionalOptions>/J /Zc:throwingNew /std:c++latest /Zc:__cplusplus %(AdditionalOptions)</AdditionalOptions>
       <Optimization>Disabled</Optimization>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <AdditionalIncludeDirectories>..\objs\langs;..\objs\settings;..\src\3rdparty\squirrel\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
@@ -223,7 +223,7 @@
       </HeaderFileName>
     </Midl>
     <ClCompile>
-      <AdditionalOptions>/J /Zc:throwingNew /std:c++latest %(AdditionalOptions)</AdditionalOptions>
+      <AdditionalOptions>/J /Zc:throwingNew /std:c++latest /Zc:__cplusplus %(AdditionalOptions)</AdditionalOptions>
       <Optimization>Full</Optimization>
       <InlineFunctionExpansion>AnySuitable</InlineFunctionExpansion>
       <IntrinsicFunctions>true</IntrinsicFunctions>
@@ -289,7 +289,7 @@
       </HeaderFileName>
     </Midl>
     <ClCompile>
-      <AdditionalOptions>/J /Zc:throwingNew /std:c++latest %(AdditionalOptions)</AdditionalOptions>
+      <AdditionalOptions>/J /Zc:throwingNew /std:c++latest /Zc:__cplusplus %(AdditionalOptions)</AdditionalOptions>
       <Optimization>Disabled</Optimization>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <AdditionalIncludeDirectories>..\objs\langs;..\objs\settings;..\src\3rdparty\squirrel\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
diff --git a/projects/settingsgen_vs142.vcxproj b/projects/settingsgen_vs142.vcxproj
index 23a4e1856..fb2f7a731 100644
--- a/projects/settingsgen_vs142.vcxproj
+++ b/projects/settingsgen_vs142.vcxproj
@@ -39,6 +39,7 @@
       <Inputs>%(Inputs)</Inputs>
     </CustomBuildStep>
     <ClCompile>
+      <AdditionalOptions>/std:c++latest /Zc:__cplusplus %(AdditionalOptions)</AdditionalOptions>
       <Optimization>MinSpace</Optimization>
       <FavorSizeOrSpeed>Size</FavorSizeOrSpeed>
       <PreprocessorDefinitions>SETTINGSGEN;WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>