Build: Use C++20 for everything except reshadefx

CMakeLists.txt

@@ -223,17 +223,13 @@ endif()
 # Prevent fmt from being built with exceptions, or being thrown at call sites.
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DFMT_EXCEPTIONS=0")
 
-# Use C++17 for building dependencies (some aren't C++20-aware, e.g. reshadefx).
-set(CMAKE_CXX_STANDARD 17)
+# Use C++20.
+set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 # Recursively include the source tree.
 include(DuckStationDependencies)
 add_subdirectory(dep)
-
-# Use C++20 for building the main libraries.
-set(CMAKE_CXX_STANDARD 20)
-set(CMAKE_CXX_STANDARD_REQUIRED ON)
 add_subdirectory(src)
 
 if(ANDROID)

dep/msvc/vsprops/Base.props

@@ -25,7 +25,7 @@
       <SDLCheck>true</SDLCheck>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <MultiProcessorCompilation>true</MultiProcessorCompilation>
-      <LanguageStandard>stdcpp17</LanguageStandard>
+      <LanguageStandard>stdcpp20</LanguageStandard>
       <ConformanceMode>true</ConformanceMode>
       <PreprocessorDefinitions>_HAS_EXCEPTIONS=0;_CRT_INTERNAL_NONSTDC_NAMES;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_WARNINGS;WIN32;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>%(AdditionalIncludeDirectories);$(DepsIncludeDir)</AdditionalIncludeDirectories>

dep/reshadefx/CMakeLists.txt

@@ -27,3 +27,7 @@ target_include_directories(reshadefx INTERFACE
   "${CMAKE_CURRENT_SOURCE_DIR}/include"
 )
 
+# reshadefx is not C++20-compatible.
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+

dep/reshadefx/reshadefx.vcxproj

@@ -33,6 +33,7 @@
     <ClCompile>
       <WarningLevel>TurnOffAllWarnings</WarningLevel>
       <AdditionalIncludeDirectories>$(ProjectDir)src;$(ProjectDir)include;$(ProjectDir)..\spirv-cross\include\spirv-cross;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <LanguageStandard>stdcpp17</LanguageStandard>
     </ClCompile>
   </ItemDefinitionGroup>
   <Import Project="..\msvc\vsprops\Targets.props" />

src/common/common.props

@@ -4,7 +4,6 @@
     <ClCompile>
       <AdditionalIncludeDirectories>$(SolutionDir)src;%(AdditionalIncludeDirectories);$(SolutionDir)dep\fast_float\include;$(SolutionDir)dep\fmt\include</AdditionalIncludeDirectories>
       <PreprocessorDefinitions>%(PreprocessorDefinitions);FMT_EXCEPTIONS=0</PreprocessorDefinitions>
-      <LanguageStandard>stdcpp20</LanguageStandard>
     </ClCompile>
   </ItemDefinitionGroup>