From 58b4946fb93b787d7a28d721fc11ee59c32a9371 Mon Sep 17 00:00:00 2001
From: Stenzek <stenzek@gmail.com>
Date: Tue, 5 Sep 2023 20:57:18 +1000
Subject: [PATCH] Build: Switch to C++20

---
 CMakeLists.txt          | 12 +++++++++---
 src/common/common.props |  1 +
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 55467ecd2..d35c29521 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -142,9 +142,7 @@ if(ANDROID)
 endif()
 
 
-# Detect C++ version support.
-set(CMAKE_CXX_STANDARD 17)
-set(CMAKE_CXX_STANDARD_REQUIRED ON)
+# Warning disables.
 if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
     include(CheckCXXFlag)
     check_cxx_flag(-Wall COMPILER_SUPPORTS_WALL)
@@ -229,8 +227,16 @@ if(BUILD_TESTS)
   enable_testing()
 endif()
 
+# Use C++17 for building dependencies (some aren't C++20-aware, e.g. reshadefx).
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
 # Recursively include the source tree.
 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)
diff --git a/src/common/common.props b/src/common/common.props
index b8ee70e4b..892e347d1 100644
--- a/src/common/common.props
+++ b/src/common/common.props
@@ -3,6 +3,7 @@
   <ItemDefinitionGroup>
     <ClCompile>
       <AdditionalIncludeDirectories>$(SolutionDir)src;%(AdditionalIncludeDirectories);$(SolutionDir)dep\gsl\include;$(SolutionDir)dep\fast_float\include;$(SolutionDir)dep\fmt\include;$(SolutionDir)dep\zlib\include;$(SolutionDir)dep\minizip\include;$(SolutionDir)dep\stb\include</AdditionalIncludeDirectories>
+      <LanguageStandard>stdcpp20</LanguageStandard>
     </ClCompile>
   </ItemDefinitionGroup>