Update instructions to use C++20 instead of C++17

Upstream is shifting towards C++20.

1 files changed, 9 insertions, 9 deletions

diff --git a/README.md b/README.md
index a3bd2dae5e..083364275a 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@ $ cd build-`uname -s|tr '[:upper:]' '[:lower:]'`-`uname -m`
 
 ```
 $ sudo port install cmake pkgconfig freealut +universal apr-util +universal boost181 +universal glm hunspell +universal freetype +universal minizip +universal pcre +universal uriparser +universal libvorbis +universal xxhashlib
-$ export LL_BUILD="-O3 -gdwarf-2 -stdlib=libc++ -mmacosx-version-min=11 -iwithsysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk -std=c++17 -fPIC -DLL_RELEASE=1 -DLL_RELEASE_FOR_DOWNLOAD=1 -DNDEBUG -DPIC -DLL_DARWIN=1"
+$ export LL_BUILD="-O3 -gdwarf-2 -stdlib=libc++ -mmacosx-version-min=11 -iwithsysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk -std=c++20 -fPIC -DLL_RELEASE=1 -DLL_RELEASE_FOR_DOWNLOAD=1 -DNDEBUG -DPIC -DLL_DARWIN=1"
 $ cmake -DCMAKE_BUILD_TYPE:STRING=Release -DADDRESS_SIZE:STRING=64 -DUSESYSTEMLIBS:BOOL=ON -DUSE_OPENAL:BOOL=ON -DUSE_FMODSTUDIO:BOOL=OFF -DENABLE_MEDIA_PLUGINS:BOOL=ON -DLL_TESTS:BOOL=OFF -DNDOF:BOOL=ON -DROOT_PROJECT_NAME:STRING=Megapahit -DVIEWER_CHANNEL:STRING=Megapahit -DVIEWER_BINARY_NAME:STRING=megapahit -DBUILD_SHARED_LIBS:BOOL=OFF -DINSTALL:BOOL=ON -DPACKAGE:BOOL=OFF -DCMAKE_INSTALL_PREFIX:PATH=newview/Megapahit.app/Contents/Resources -DCMAKE_OSX_ARCHITECTURES:STRING=`uname -m` -DCMAKE_OSX_DEPLOYMENT_TARGET:STRING=11 -DENABLE_SIGNING:BOOL=ON -DSIGNING_IDENTITY:STRING=- ../indra
 $ make -j`sysctl -n hw.ncpu`
 $ make install
@@ -32,7 +32,7 @@ $ open newview/Megapahit.app
 
 ```
 $ sudo apt install cmake pkg-config libxml2-utils libalut-dev libaprutil1-dev libboost-fiber1.81-dev libboost-json1.81-dev libboost-program-options1.81-dev libboost-regex1.81-dev libboost-url1.81-dev libexpat1-dev libfltk1.3-dev libfontconfig-dev libfreetype-dev libglu1-mesa-dev libhunspell-dev libjpeg-dev libmeshoptimizer-dev libminizip-dev libnghttp2-dev libpcre3-dev libpipewire-0.3-dev libpng-dev libsdl2-dev liburiparser-dev libvlc-dev libvlccore-dev libvorbis-dev libxft-dev libxml2-dev libxxhash-dev
-$ export LL_BUILD="-O3 -std=c++17 -fPIC -DLL_LINUX=1"
+$ export LL_BUILD="-O3 -std=c++20 -fPIC -DLL_LINUX=1"
 $ cmake -DCMAKE_BUILD_TYPE:STRING=Release -DADDRESS_SIZE:STRING=64 -DUSESYSTEMLIBS:BOOL=ON -DUSE_OPENAL:BOOL=ON -DUSE_FMODSTUDIO:BOOL=OFF -DENABLE_MEDIA_PLUGINS:BOOL=ON -DLL_TESTS:BOOL=OFF -DNDOF:BOOL=ON -DROOT_PROJECT_NAME:STRING=Megapahit -DVIEWER_CHANNEL:STRING=Megapahit -DVIEWER_BINARY_NAME:STRING=megapahit -DBUILD_SHARED_LIBS:BOOL=OFF -DINSTALL:BOOL=ON -DPACKAGE:BOOL=ON ../indra
 $ make -j`nproc`
 $ cpack -G DEB
@@ -44,7 +44,7 @@ $ megapahit
 
 ```
 $ sudo apt install cmake pkg-config libxml2-utils libaprutil1-dev libboost-fiber-dev libboost-json-dev libboost-program-options-dev libboost-regex-dev libboost-url-dev libexpat1-dev libfltk1.3-dev libfontconfig-dev libfreetype-dev libglu1-mesa-dev libhunspell-dev libjpeg-dev libmeshoptimizer-dev libminizip-dev libnanosvg-dev libnghttp2-dev libpcre3-dev libpipewire-0.3-dev libpng-dev libsdl2-dev liburiparser-dev libvlc-dev libvlccore-dev libvorbis-dev libxft-dev libxml2-dev libxxhash-dev
-$ export LL_BUILD="-O3 -std=c++17 -fPIC -DLL_LINUX=1"
+$ export LL_BUILD="-O3 -std=c++20 -fPIC -DLL_LINUX=1"
 $ cmake -DCMAKE_BUILD_TYPE:STRING=Release -DADDRESS_SIZE:STRING=64 -DUSESYSTEMLIBS:BOOL=ON -DUSE_OPENAL:BOOL=OFF -DUSE_FMODSTUDIO:BOOL=ON -DENABLE_MEDIA_PLUGINS:BOOL=ON -DLL_TESTS:BOOL=OFF -DNDOF:BOOL=ON -DROOT_PROJECT_NAME:STRING=Megapahit -DVIEWER_CHANNEL:STRING=Megapahit -DVIEWER_BINARY_NAME:STRING=megapahit -DBUILD_SHARED_LIBS:BOOL=OFF -DINSTALL:BOOL=ON -DPACKAGE:BOOL=ON ../indra
 $ make -j`nproc`
 $ cpack -G DEB
@@ -56,7 +56,7 @@ $ megapahit
 
 ```
 $ sudo dnf install cmake gcc-c++ patch patchelf rpm-build apr-util-devel boost-devel boost-url expat-devel fltk-devel mesa-libGLU-devel hunspell-devel minizip-ng-compat-devel libnghttp2-devel nanosvg-devel pipewire-devel pulseaudio-libs-devel SDL2-devel uriparser-devel vlc-devel libvorbis-devel libXcursor-devel libXfixes-devel libXinerama-devel xxhash-devel
-$ export LL_BUILD="-O3 -std=c++17 -fPIC -DLL_LINUX=1"
+$ export LL_BUILD="-O3 -std=c++20 -fPIC -DLL_LINUX=1"
 $ cmake -DCMAKE_BUILD_TYPE:STRING=Release -DADDRESS_SIZE:STRING=64 -DUSESYSTEMLIBS:BOOL=ON -DUSE_OPENAL:BOOL=OFF -DUSE_FMODSTUDIO:BOOL=ON -DENABLE_MEDIA_PLUGINS:BOOL=ON -DLL_TESTS:BOOL=OFF -DNDOF:BOOL=ON -DROOT_PROJECT_NAME:STRING=Megapahit -DVIEWER_CHANNEL:STRING=Megapahit -DVIEWER_BINARY_NAME:STRING=megapahit -DBUILD_SHARED_LIBS:BOOL=OFF -DINSTALL:BOOL=ON -DPACKAGE:BOOL=ON ../indra
 $ make -j`nproc`
 $ cpack -G RPM
@@ -68,7 +68,7 @@ $ megapahit
 
 ```
 $ sudo zypper install gcc-c++ patchelf apr-util-devel boost-devel libboost_program_options-devel libboost_url1_86_0-devel libboost_context-devel libboost_fiber-devel libboost_filesystem-devel libboost_regex-devel libboost_system-devel libboost_thread-devel libexpat-devel fltk-devel glu-devel hunspell-devel minizip-devel nanosvg-devel libnghttp2-devel pcre-devel pipewire-devel libpulse-devel SDL2-devel uriparser-devel vlc-devel libvorbis-devel xxhash-devel zlib-ng-devel libXrender-devel libXcursor-devel libXfixes-devel libXext-devel libXft-devel libXinerama-devel freetype2-devel fontconfig-devel libjpeg8-devel libjpeg8-devel freealut-devel
-$ export LL_BUILD="-O3 -std=c++17 -fPIC -DLL_LINUX=1"
+$ export LL_BUILD="-O3 -std=c++20 -fPIC -DLL_LINUX=1"
 $ cmake -DCMAKE_BUILD_TYPE:STRING=Release -DADDRESS_SIZE:STRING=64 -DUSESYSTEMLIBS:BOOL=ON -DUSE_OPENAL:BOOL=ON -DENABLE_MEDIA_PLUGINS:BOOL=ON -DLL_TESTS:BOOL=OFF -DNDOF:BOOL=ON -DROOT_PROJECT_NAME:STRING=Megapahit -DVIEWER_CHANNEL:STRING=Megapahit -DVIEWER_BINARY_NAME:STRING=megapahit -DBUILD_SHARED_LIBS:BOOL=OFF -DINSTALL:BOOL=ON -DPACKAGE:BOOL=ON ../indra
 $ make -j`nproc`
 $ cpack -G RPM
@@ -80,7 +80,7 @@ $ megapahit
 ### Arch
 ```
 $ sudo pacman -S cmake base-devel python apr-util boost fltk glm glu hunspell minizip nanosvg libnghttp2 pcre libpipewire sdl2 uriparser vlc libvorbis xxhash
-$ export LL_BUILD="-O3 -std=c++17 -fPIC -DLL_LINUX=1"
+$ export LL_BUILD="-O3 -std=c++20 -fPIC -DLL_LINUX=1"
 $ cmake -DCMAKE_BUILD_TYPE:STRING=Release -DADDRESS_SIZE:STRING=64 -DUSESYSTEMLIBS:BOOL=ON -DUSE_OPENAL:BOOL=OFF -DUSE_FMODSTUDIO:BOOL=ON -DENABLE_MEDIA_PLUGINS:BOOL=ON -DLL_TESTS:BOOL=OFF -DNDOF:BOOL=OFF -DROOT_PROJECT_NAME:STRING=Megapahit -DVIEWER_CHANNEL:STRING=Megapahit -DVIEWER_BINARY_NAME:STRING=megapahit -DBUILD_SHARED_LIBS:BOOL=OFF -DINSTALL:BOOL=ON -DPACKAGE:BOOL=ON -DCMAKE_INSTALL_PREFIX:PATH=/usr ../indra
 $ make -j`nproc`
 $ makepkg -R
@@ -93,7 +93,7 @@ $ megapahit
 $ sudo su -
 # portmaster devel/cmake devel/pkgconf audio/freealut devel/apr1 devel/boost-libs x11-toolkits/fltk math/glm textproc/hunspell misc/meshoptimizer archivers/minizip graphics/nanosvg www/libnghttp2 devel/pcre devel/sdl20 net/uriparser multimedia/vlc audio/libvorbis devel/xxhash
 # exit
-$ setenv LL_BUILD "-O3 -std=c++17 -fPIC"
+$ setenv LL_BUILD "-O3 -std=c++20 -fPIC"
 $ cmake -DCMAKE_BUILD_TYPE:STRING=Release -DADDRESS_SIZE:STRING=64 -DUSESYSTEMLIBS:BOOL=ON -DUSE_OPENAL:BOOL=ON -DUSE_FMODSTUDIO:BOOL=OFF -DENABLE_MEDIA_PLUGINS:BOOL=ON -DLL_TESTS:BOOL=OFF -DNDOF:BOOL=OFF -DROOT_PROJECT_NAME:STRING=Megapahit -DVIEWER_CHANNEL:STRING=Megapahit -DVIEWER_BINARY_NAME:STRING=megapahit -DBUILD_SHARED_LIBS:BOOL=OFF -DINSTALL:BOOL=ON -DPACKAGE:BOOL=ON ../indra
 $ make -j`nproc`
 $ sudo cpack -G FREEBSD
@@ -107,7 +107,7 @@ $ megapahit
 $ sudo su -
 # emerge cmake pkgconf freealut apr-util boost fltk glm hunspell minizip-ng nanosvg nghttp2 libpcre media-video/pipewire libsdl2 uriparser vlc libvorbis dev-libs/xxhash
 # exit
-$ export LL_BUILD="-O3 -std=c++17 -fPIC -DLL_LINUX=1"
+$ export LL_BUILD="-O3 -std=c++20 -fPIC -DLL_LINUX=1"
 $ cmake -DCMAKE_BUILD_TYPE:STRING=Release -DADDRESS_SIZE:STRING=64 -DUSESYSTEMLIBS:BOOL=ON -DUSE_OPENAL:BOOL=ON -DUSE_FMODSTUDIO:BOOL=OFF -DENABLE_MEDIA_PLUGINS:BOOL=ON -DLL_TESTS:BOOL=OFF -DNDOF:BOOL=OFF -DROOT_PROJECT_NAME:STRING=Megapahit -DVIEWER_CHANNEL:STRING=Megapahit -DVIEWER_BINARY_NAME:STRING=megapahit -DBUILD_SHARED_LIBS:BOOL=OFF -DINSTALL:BOOL=ON -DPACKAGE:BOOL=OFF ../indra
 $ make -j`nproc`
 ```
@@ -115,7 +115,7 @@ $ make -j`nproc`
 ### Windows
 ```
 $ pacman -S mingw-w64-clang-aarch64-cmake mingw-w64-clang-aarch64-pkgconf mingw-w64-clang-aarch64-freealut mingw-w64-clang-aarch64-apr-util mingw-w64-clang-aarch64-boost mingw-w64-clang-aarch64-fltk mingw-w64-clang-aarch64-glm mingw-w64-clang-aarch64-hunspell mingw-w64-clang-aarch64-minizip mingw-w64-clang-aarch64-nghttp2 mingw-w64-clang-aarch64-pcre mingw-w64-clang-aarch64-SDL2 mingw-w64-clang-aarch64-uriparser mingw-w64-clang-aarch64-vlc mingw-w64-clang-aarch64-libvorbis mingw-w64-clang-aarch64-xxhash
-$ export LL_BUILD="-O3 -std=c++17 -fPIC -DLL_WINDOWS=1"
+$ export LL_BUILD="-O3 -std=c++20 -fPIC -DLL_WINDOWS=1"
 $ cmake -DCMAKE_BUILD_TYPE:STRING=Release -DADDRESS_SIZE:STRING=64 -DUSESYSTEMLIBS:BOOL=ON -DUSE_OPENAL:BOOL=ON -DUSE_FMODSTUDIO:BOOL=OFF -DENABLE_MEDIA_PLUGINS:BOOL=OFF -DLL_TESTS:BOOL=OFF -DNDOF:BOOL=OFF -DROOT_PROJECT_NAME:STRING=Megapahit -DVIEWER_CHANNEL:STRING=Megapahit -DVIEWER_BINARY_NAME:STRING=megapahit -DBUILD_SHARED_LIBS:BOOL=OFF -DINSTALL:BOOL=OFF -DPACKAGE:BOOL=OFF ../indra
 ```