Merge branch 'feature/ci-test-with-cpp-20' into 'master'

[ci][default] allow setting max_cxx_standard and add C++20 pipeline

Closes #1169

See merge request !3172

.gitlab-ci.yml

@@ -107,11 +107,11 @@ full-dune-latest-release-clang:
   variables:
     IMAGE: $IMAGE_REGISTRY_URL/full:dune-$DUMUX_CI_DUNE_LATEST_RELEASE-clang-ubuntu-20.04
 
-full-dune-master-gcc:
+full-dune-master-gcc-cpp-20:
   extends: .base-trigger
   variables:
-    IMAGE: $IMAGE_REGISTRY_URL/full:dune-master-gcc-ubuntu-20.04
-
+    IMAGE: $IMAGE_REGISTRY_URL/full:dune-master-gcc-ubuntu-22.04
+    CXX_MAX_STANDARD: "20"
 
 ##################################
 # additional scheduled pipelines #
@@ -120,6 +120,10 @@ full-dune-master-clang:
   variables:
     IMAGE: $IMAGE_REGISTRY_URL/full:dune-master-clang-ubuntu-20.04
 
+full-dune-master-gcc:
+  extends: .non-mr-trigger
+  variables:
+    IMAGE: $IMAGE_REGISTRY_URL/full:dune-master-gcc-ubuntu-20.04
 
 ################################################
 # trigger test pipelines of downstream modules #

.gitlab-ci/default.yml

@@ -21,13 +21,17 @@ workflow:
 variables:
   MR_TARGET_BRANCH_NAME: ""
   REFERENCE_SHA: ""
+  CXX_MAX_STANDARD: "17"
 
 
 configure:
   stage: configure
   script:
-    - dunecontrol --opts=$DUNE_OPTS_FILE --current configure
-    - dunecontrol --opts=$DUNE_OPTS_FILE --current make -j8
+    - |
+      echo "source ${DUNE_OPTS_FILE}" > opts_file.opts
+      echo "CMAKE_FLAGS=\"\${CMAKE_FLAGS} -DCXX_MAX_STANDARD=${CXX_MAX_STANDARD}\"" >> opts_file.opts
+    - dunecontrol --opts=opts_file.opts --current configure
+    - dunecontrol --opts=opts_file.opts --current make -j8
     # cache state of the Dune virtual env for Python if it exists (Dune 2.9)
     - |
       if [ -d "/dune/modules/dune-common/build-cmake/dune-env" ]; then

CHANGELOG.md

@@ -3,6 +3,8 @@ Differences Between DuMu<sup>x</sup> 3.6 and DuMu<sup>x</sup> 3.5
 
 ### General changes / structure
 
+- __Testing/CI__: Dumux is now tested with C++20 flag enabled in addition to C++17 (which is still the minimum requirement)
+
 ### Improvements and Enhancements
 
 - __Discretization__: There is now defaults for `FluxVariablesCache` and `FluxVariablesCacheFiller` for box/cctpfa/ccmpfa/staggered