From aa3358f7094803e19d2ccd7d4c5b998a255fbb27 Mon Sep 17 00:00:00 2001
From: Luis Antonio Obis Aparicio <luis.antonio.obis@gmail.com>
Date: Wed, 6 Dec 2023 02:14:49 -0600
Subject: [PATCH] c++ standard to 20

---
 .github/workflows/build-test.yaml | 4 ++--
 CMakeLists.txt                    | 2 +-
 Dockerfile                        | 6 +++---
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/.github/workflows/build-test.yaml b/.github/workflows/build-test.yaml
index d45f0cc..2d61e8f 100644
--- a/.github/workflows/build-test.yaml
+++ b/.github/workflows/build-test.yaml
@@ -54,7 +54,7 @@ jobs:
           git -C xerces-source checkout tags/v3.2.4
           mkdir -p ${{ github.workspace }}/xerces-source/build
           cd ${{ github.workspace }}/xerces-source/build
-          cmake .. -DCMAKE_INSTALL_PREFIX=${{ github.workspace }}/xerces -DCMAKE_CXX_STANDARD=23 -DBUILD_SHARED_LIBS=OFF -DCMAKE_BUILD_TYPE=Release -Dnetwork-accessor=socket -Dtranscoder=iconv -DCMAKE_CXX_FLAGS=-fPIC -DCMAKE_C_FLAGS=-fPIC
+          cmake .. -DCMAKE_INSTALL_PREFIX=${{ github.workspace }}/xerces -DCMAKE_CXX_STANDARD=20 -DBUILD_SHARED_LIBS=OFF -DCMAKE_BUILD_TYPE=Release -Dnetwork-accessor=socket -Dtranscoder=iconv -DCMAKE_CXX_FLAGS=-fPIC -DCMAKE_C_FLAGS=-fPIC
           make install -j$(nproc)
 
       - name: Cache Geant4 Installation
@@ -70,7 +70,7 @@ jobs:
           git clone https://github.com/Geant4/geant4.git ${{ github.workspace }}/geant4-source --depth 1 --branch v${{ matrix.geant4-version }}
           mkdir -p ${{ github.workspace }}/geant4-source/build
           cd ${{ github.workspace }}/geant4-source/build
-          cmake .. -DCMAKE_INSTALL_PREFIX=${{ github.workspace }}/geant4 -DXERCESC_ROOT_DIR=${{ github.workspace }}/xerces -DCMAKE_CXX_STANDARD=23 -DCMAKE_BUILD_TYPE=Release -DGEANT4_USE_GDML=ON -DGEANT4_INSTALL_EXAMPLES=OFF -DGEANT4_INSTALL_DATA=OFF -DGEANT4_BUILD_TLS_MODEL=global-dynamic -DCMAKE_CXX_FLAGS=-fPIC -DCMAKE_C_FLAGS=-fPIC -DGEANT4_USE_SYSTEM_EXPAT=OFF -DBUILD_STATIC_LIBS=ON -DBUILD_SHARED_LIBS=OFF
+          cmake .. -DCMAKE_INSTALL_PREFIX=${{ github.workspace }}/geant4 -DXERCESC_ROOT_DIR=${{ github.workspace }}/xerces -DCMAKE_CXX_STANDARD=20 -DCMAKE_BUILD_TYPE=Release -DGEANT4_USE_GDML=ON -DGEANT4_INSTALL_EXAMPLES=OFF -DGEANT4_INSTALL_DATA=OFF -DGEANT4_BUILD_TLS_MODEL=global-dynamic -DCMAKE_CXX_FLAGS=-fPIC -DCMAKE_C_FLAGS=-fPIC -DGEANT4_USE_SYSTEM_EXPAT=OFF -DBUILD_STATIC_LIBS=ON -DBUILD_SHARED_LIBS=OFF
           make install -j$(nproc)
 
   install-geant4-datasets:
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6a86eb7..3e3a1b4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -12,7 +12,7 @@ project(
 
 set(PYTHON_MODULE_NAME geant4_application)
 
-set(CMAKE_CXX_STANDARD 23)
+set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
diff --git a/Dockerfile b/Dockerfile
index 7866baa..85599d3 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,7 +8,7 @@ RUN apt-get update -qq && apt-get install -q -y --no-install-recommends \
 # Install a more recent CMake version
 RUN pip install cmake
 
-ARG CMAKE_CXX_STANDARD=23
+ARG CMAKE_CXX_STANDARD=20
 ARG GEANT4_VERSION=11.1.3
 ARG XERCES_VERSION=3.2.4
 
@@ -16,7 +16,7 @@ RUN git clone https://github.com/apache/xerces-c.git /tmp/xerces \
     && git -C /tmp/xerces checkout tags/v${XERCES_VERSION} \
     && cmake -G Ninja -B /tmp/xerces/build -S /tmp/xerces \
     -DCMAKE_INSTALL_PREFIX=/opt/xerces \
-    -DCMAKE_CXX_STANDARD=23 \
+    -DCMAKE_CXX_STANDARD=20 \
     -DCMAKE_BUILD_TYPE=Release \
     -DBUILD_SHARED_LIBS=OFF \
     -Dnetwork-accessor=socket \
@@ -30,7 +30,7 @@ RUN git clone https://github.com/Geant4/geant4.git /tmp/geant4 --branch=v${GEANT
     && cmake -G Ninja -B /tmp/geant4/build -S /tmp/geant4 \
     -DCMAKE_INSTALL_PREFIX=/opt/geant4 \
     -DXERCESC_ROOT_DIR=/opt/xerces \
-    -DCMAKE_CXX_STANDARD=23 \
+    -DCMAKE_CXX_STANDARD=20 \
     -DCMAKE_BUILD_TYPE=Release \
     -DGEANT4_USE_GDML=ON \
     -DGEANT4_INSTALL_EXAMPLES=OFF \