diff --git a/.github/setenv.sh b/.github/setenv.sh
index e173da42..0ee91fd5 100644
--- a/.github/setenv.sh
+++ b/.github/setenv.sh
@@ -18,7 +18,7 @@ function c4_show_info()
     pwd
     ls -lFhp
     echo "BITLINKS=$BITLINKS"
-    for bl in shared64 static64 shared32 static32 ; do
+    for bl in shared64 static64 shared32 static32 arm64 arm64shared arm64static shared64arm static64arm arm32 arm32shared arm32static shared32arm static32arm arm ; do
         if _c4skipbitlink $bl ; then
             echo "skip $bl"
         else
@@ -69,8 +69,20 @@ function _c4bits()
 function _c4linktype()
 {
     case "$1" in
-        shared64|shared32) echo shared ;;
-        static64|static32) echo static ;;
+        shared64|shared32|arm64static|arm32static) echo shared ;;
+        static64|static32|arm64shared|arm32shared|arm64|arm32|arm) echo static ;;
+        *) exit 1 ;;
+    esac
+}
+
+function _c4vsarchtype()
+{
+    # https://cmake.org/cmake/help/git-stage/generator/Visual%20Studio%2016%202019.html
+    case "$1" in
+        shared64|static64) echo x64 ;;
+        shared32|static32) echo Win32 ;;
+        arm64|arm64shared|arm64static|shared64arm|static64arm) echo ARM64 ;;
+        arm32|arm32shared|arm32static|shared32arm|static32arm|arm) echo ARM ;;
         *) exit 1 ;;
     esac
 }
@@ -257,19 +269,21 @@ function c4_cfg_test()
     # quoted strings in variables and then expand the variables with correct quotes
     # so we have to do this precious jewell of chicanery:
     case "$CXX_" in
+        vs2022)
+            cmake -S $PROJ_DIR -B $build_dir -DCMAKE_INSTALL_PREFIX="$install_dir" \
+                  -G 'Visual Studio 17 2022' -A $(_c4vsarchtype $id) \
+                  -DCMAKE_BUILD_TYPE=$BT $CMFLAGS
+            ;;
         vs2019)
-            g='Visual Studio 16 2019'
-            case "$bits" in
-                64) a=x64 ;;
-                32) a=Win32 ;;
-            esac
             cmake -S $PROJ_DIR -B $build_dir -DCMAKE_INSTALL_PREFIX="$install_dir" \
-                  -DCMAKE_BUILD_TYPE=$BT -G "$g" -A $a $CMFLAGS
+                  -G 'Visual Studio 16 2019' -A $(_c4vsarchtype $id) \
+                  -DCMAKE_BUILD_TYPE=$BT $CMFLAGS
             ;;
         vs2017)
             case "$bits" in
                 64) g="Visual Studio 15 2017 Win64" ;;
                 32) g="Visual Studio 15 2017" ;;
+                *) exit 1 ;;
             esac
             cmake -S $PROJ_DIR -B $build_dir -DCMAKE_INSTALL_PREFIX="$install_dir" \
                   -DCMAKE_BUILD_TYPE=$BT -G "$g" $CMFLAGS
@@ -353,7 +367,7 @@ function _addprojflags()
 function _c4_parallel_build_flags()
 {
     case "$CXX_" in
-        vs2019|vs2017|vs2015)
+        vs2022|vs2019|vs2017|vs2015)
             # https://docs.microsoft.com/en-us/visualstudio/msbuild/msbuild-command-line-reference?view=vs-2019
             # https://stackoverflow.com/questions/2619198/how-to-get-number-of-cores-in-win32
             if [ -z "$NUM_JOBS_BUILD" ] ; then
@@ -390,7 +404,7 @@ function _c4_parallel_build_flags()
 function _c4_generator_build_flags()
 {
     case "$CXX_" in
-        vs2019|vs2017|vs2015)
+        vs2022|vs2019|vs2017|vs2015)
             ;;
         xcode)
             # WTF???
diff --git a/.github/workflows/benchmarks.yml b/.github/workflows/benchmarks.yml
index 886cd59f..7df80966 100644
--- a/.github/workflows/benchmarks.yml
+++ b/.github/workflows/benchmarks.yml
@@ -42,12 +42,12 @@ jobs:
           - {std: 17, cxx: g++-10, bt: Release, os: ubuntu-18.04, bitlinks: static64 static32}
           - {std: 20, cxx: g++-10, bt: Debug  , os: ubuntu-18.04, bitlinks: static64 static32}
           - {std: 20, cxx: g++-10, bt: Release, os: ubuntu-18.04, bitlinks: static64 static32}
-          - {std: 11, cxx: vs2019, bt: Debug  , os: windows-2019, bitlinks: static64 static32}
-          - {std: 11, cxx: vs2019, bt: Release, os: windows-2019, bitlinks: static64 static32}
-          - {std: 17, cxx: vs2019, bt: Debug  , os: windows-2019, bitlinks: static64 static32}
-          - {std: 17, cxx: vs2019, bt: Release, os: windows-2019, bitlinks: static64 static32}
-          - {std: 20, cxx: vs2019, bt: Debug  , os: windows-2019, bitlinks: static64 static32}
-          - {std: 20, cxx: vs2019, bt: Release, os: windows-2019, bitlinks: static64 static32}
+          - {std: 11, cxx: vs2022, bt: Debug  , os: windows-2022, bitlinks: static64 static32}
+          - {std: 11, cxx: vs2022, bt: Release, os: windows-2022, bitlinks: static64 static32}
+          - {std: 17, cxx: vs2022, bt: Debug  , os: windows-2022, bitlinks: static64 static32}
+          - {std: 17, cxx: vs2022, bt: Release, os: windows-2022, bitlinks: static64 static32}
+          - {std: 20, cxx: vs2022, bt: Debug  , os: windows-2022, bitlinks: static64 static32}
+          - {std: 20, cxx: vs2022, bt: Release, os: windows-2022, bitlinks: static64 static32}
     env: {BM: ON, STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
     steps:
       # use fetch-depth to ensure all tags are fetched
diff --git a/.github/workflows/clang.yml b/.github/workflows/clang.yml
new file mode 100644
index 00000000..640369af
--- /dev/null
+++ b/.github/workflows/clang.yml
@@ -0,0 +1,230 @@
+name: clang
+
+defaults:
+  #if: "!contains(github.event.head_commit.message, 'skip ci')"  # SKIP
+  run:
+    # Use a bash shell so we can use the same syntax for environment variable
+    # access regardless of the host operating system
+    shell: bash -e -x {0}
+
+on:
+  # https://github.community/t/how-to-trigger-an-action-on-push-or-pull-request-but-not-both/16662
+  workflow_dispatch:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
+
+env:
+  PROJ_PFX_TARGET: c4core-
+  PROJ_PFX_CMAKE: C4CORE_
+  CMAKE_FLAGS:
+  NUM_JOBS_BUILD: # 4
+
+
+# ubuntu-20.04:
+#   # https://github.com/actions/virtual-environments/blob/main/images/linux/Ubuntu2004-README.md
+#   gcc: 7.5.0, 8.4.0, 9.3.0, 10.2.0
+#   clang: 8.0.1, 9.0.1, 10.0.0
+# ubuntu-18.04:
+#   # https://github.com/actions/virtual-environments/blob/main/images/linux/Ubuntu1804-README.md
+#   gcc: 7.5.0, 8.4.0, 9.3.0, 10.1.0
+#   clang: 6.0.0, 8.0.0, 9.0.0
+# macos-11.0: macOS Big Sur 11.0
+#   # https://github.com/actions/virtual-environments/blob/main/images/macos/macos-11.0-Readme.md
+#   Xcode 12.1 11.7
+#   clang/LLVM 10.0.1
+#   gcc-8 gcc-9
+# macos-10.15: macOS Catalina 10.15
+#   # https://github.com/actions/virtual-environments/blob/main/images/macos/macos-10.15-Readme.md
+#   Xcode 12.1 11.7
+#   clang/LLVM 11.0.0
+#   gcc-8 gcc-9
+# windows-2019:
+#   # https://github.com/actions/virtual-environments/blob/main/images/win/Windows2019-Readme.md
+#   vs2019
+# windows-2016:
+#   # https://github.com/actions/virtual-environments/blob/main/images/win/Windows2016-Readme.md
+#   vs2017
+
+jobs:
+
+  #----------------------------------------------------------------------------
+  clang_canary:
+    name: clang_canary/${{matrix.cxx}}/c++${{matrix.std}}/${{matrix.bt}}
+    continue-on-error: true
+    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
+    runs-on: ${{matrix.os}}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - {std: 20, cxx: clang++-10 , bt: Debug  , os: ubuntu-18.04, bitlinks: shared64 static32}
+          - {std: 20, cxx: clang++-10 , bt: Release, os: ubuntu-18.04, bitlinks: shared64 static32}
+          - {std: 11, cxx: clang++-6.0, bt: Debug  , os: ubuntu-18.04, bitlinks: shared64 static32}
+          - {std: 11, cxx: clang++-6.0, bt: Release, os: ubuntu-18.04, bitlinks: shared64 static32}
+    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
+    steps:
+      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
+      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
+      - {name: show info, run: source .github/setenv.sh && c4_show_info}
+      - name: shared64-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared64
+      - {name: shared64-build, run: source .github/setenv.sh && c4_build_test shared64}
+      - {name: shared64-run, run: source .github/setenv.sh && c4_run_test shared64}
+      - {name: shared64-pack, run: source .github/setenv.sh && c4_package shared64}
+      - name: static64-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static64
+      - {name: static64-build, run: source .github/setenv.sh && c4_build_test static64}
+      - {name: static64-run, run: source .github/setenv.sh && c4_run_test static64}
+      - {name: static64-pack, run: source .github/setenv.sh && c4_package static64}
+      - name: static32-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static32
+      - {name: static32-build, run: source .github/setenv.sh && c4_build_test static32}
+      - {name: static32-run, run: source .github/setenv.sh && c4_run_test static32}
+      - {name: static32-pack, run: source .github/setenv.sh && c4_package static32}
+      - name: shared32-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared32
+      - {name: shared32-build, run: source .github/setenv.sh && c4_build_test shared32}
+      - {name: shared32-run, run: source .github/setenv.sh && c4_run_test shared32}
+      - {name: shared32-pack, run: source .github/setenv.sh && c4_package shared32}
+
+  #----------------------------------------------------------------------------
+  clang_extended:
+    name: clang_extended/${{matrix.cxx}}/c++${{matrix.std}}/${{matrix.bt}}/vg${{matrix.vg}}
+    continue-on-error: true
+    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
+    runs-on: ${{matrix.os}}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - {std: 20, cxx: clang++-10 , bt: Debug  , vg: on, os: ubuntu-18.04}
+          - {std: 20, cxx: clang++-10 , bt: Release, vg: on, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-9  , bt: Debug  , vg: on, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-9  , bt: Release, vg: on, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-8  , bt: Debug  , vg: on, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-8  , bt: Release, vg: on, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-7  , bt: Debug  , vg: on, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-7  , bt: Release, vg: on, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-6.0, bt: Debug  , vg: on, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-6.0, bt: Release, vg: on, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-5.0, bt: Debug  , vg: on, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-5.0, bt: Release, vg: on, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-4.0, bt: Debug  , vg: on, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-4.0, bt: Release, vg: on, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-3.9, bt: Debug  , vg: on, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-3.9, bt: Release, vg: on, os: ubuntu-18.04}
+    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
+    steps:
+      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
+      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
+      - {name: show info, run: source .github/setenv.sh && c4_show_info}
+      - name: shared64-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared64
+      - {name: shared64-build, run: source .github/setenv.sh && c4_build_test shared64}
+      - {name: shared64-run, run: source .github/setenv.sh && c4_run_test shared64}
+      - {name: shared64-pack, run: source .github/setenv.sh && c4_package shared64}
+      - name: static64-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static64
+      - {name: static64-build, run: source .github/setenv.sh && c4_build_test static64}
+      - {name: static64-run, run: source .github/setenv.sh && c4_run_test static64}
+      - {name: static64-pack, run: source .github/setenv.sh && c4_package static64}
+      - name: static32-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static32
+      - {name: static32-build, run: source .github/setenv.sh && c4_build_test static32}
+      - {name: static32-run, run: source .github/setenv.sh && c4_run_test static32}
+      - {name: static32-pack, run: source .github/setenv.sh && c4_package static32}
+      - name: shared32-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared32
+      - {name: shared32-build, run: source .github/setenv.sh && c4_build_test shared32}
+      - {name: shared32-run, run: source .github/setenv.sh && c4_run_test shared32}
+      - {name: shared32-pack, run: source .github/setenv.sh && c4_package shared32}
+
+  #----------------------------------------------------------------------------
+  clang_sanitize:
+    name: clang_sanitize/c++${{matrix.std}}/${{matrix.bt}}/vg${{matrix.vg}}
+    continue-on-error: true
+    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
+    runs-on: ${{matrix.os}}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          # these jobs take much longer, so run only one bitlink pair per job to profit from parallelism
+          - {std: 11, cxx: clang++-10 , bt: Debug  , vg: ON, san: ALL, bitlinks: shared64 static64, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-10 , bt: Debug  , vg: ON, san: ALL, bitlinks: shared32 static32, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-10 , bt: Release, vg: ON, san: ALL, bitlinks: shared64 static64, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-10 , bt: Release, vg: ON, san: ALL, bitlinks: shared32 static32, os: ubuntu-18.04}
+          - {std: 14, cxx: clang++-10 , bt: Debug  , vg: ON, san: ALL, bitlinks: shared64 static64, os: ubuntu-18.04}
+          - {std: 14, cxx: clang++-10 , bt: Debug  , vg: ON, san: ALL, bitlinks: shared32 static32, os: ubuntu-18.04}
+          - {std: 14, cxx: clang++-10 , bt: Release, vg: ON, san: ALL, bitlinks: shared64 static64, os: ubuntu-18.04}
+          - {std: 14, cxx: clang++-10 , bt: Release, vg: ON, san: ALL, bitlinks: shared32 static32, os: ubuntu-18.04}
+          - {std: 17, cxx: clang++-10 , bt: Debug  , vg: ON, san: ALL, bitlinks: shared64 static64, os: ubuntu-18.04}
+          - {std: 17, cxx: clang++-10 , bt: Debug  , vg: ON, san: ALL, bitlinks: shared32 static32, os: ubuntu-18.04}
+          - {std: 17, cxx: clang++-10 , bt: Release, vg: ON, san: ALL, bitlinks: shared64 static64, os: ubuntu-18.04}
+          - {std: 17, cxx: clang++-10 , bt: Release, vg: ON, san: ALL, bitlinks: shared32 static32, os: ubuntu-18.04}
+          - {std: 20, cxx: clang++-10 , bt: Debug  , vg: ON, san: ALL, bitlinks: shared64 static64, os: ubuntu-18.04}
+          - {std: 20, cxx: clang++-10 , bt: Debug  , vg: ON, san: ALL, bitlinks: shared32 static32, os: ubuntu-18.04}
+          - {std: 20, cxx: clang++-10 , bt: Release, vg: ON, san: ALL, bitlinks: shared64 static64, os: ubuntu-18.04}
+          - {std: 20, cxx: clang++-10 , bt: Release, vg: ON, san: ALL, bitlinks: shared32 static32, os: ubuntu-18.04}
+    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
+    steps:
+      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
+      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
+      - {name: show info, run: source .github/setenv.sh && c4_show_info}
+      - name: shared64-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared64
+      - {name: shared64-build, run: source .github/setenv.sh && c4_build_test shared64}
+      - {name: shared64-run, run: source .github/setenv.sh && c4_run_test shared64}
+      - {name: shared64-pack, run: source .github/setenv.sh && c4_package shared64}
+      - name: static64-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static64
+      - {name: static64-build, run: source .github/setenv.sh && c4_build_test static64}
+      - {name: static64-run, run: source .github/setenv.sh && c4_run_test static64}
+      - {name: static64-pack, run: source .github/setenv.sh && c4_package static64}
+      - name: static32-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static32
+      - {name: static32-build, run: source .github/setenv.sh && c4_build_test static32}
+      - {name: static32-run, run: source .github/setenv.sh && c4_run_test static32}
+      - {name: static32-pack, run: source .github/setenv.sh && c4_package static32}
+      - name: shared32-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared32
+      - {name: shared32-build, run: source .github/setenv.sh && c4_build_test shared32}
+      - {name: shared32-run, run: source .github/setenv.sh && c4_run_test shared32}
+      - {name: shared32-pack, run: source .github/setenv.sh && c4_package shared32}
+
+  #----------------------------------------------------------------------------
+#  # https://blog.kitware.com/static-checks-with-cmake-cdash-iwyu-clang-tidy-lwyu-cpplint-and-cppcheck/
+#  static_analysis:
+#    continue-on-error: true
+#    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
+#    runs-on: ${{matrix.os}}
+#    strategy:
+#      fail-fast: false
+#      matrix:
+#        include:
+#          # these jobs take much longer, so run only one bitlink pair per job to profit from parallelism
+#          - {std: 11, cxx: clang++-10, bt: Debug  , bitlinks: shared64, os: ubuntu-18.04}
+#          - {std: 11, cxx: clang++-10, bt: Release, bitlinks: shared64, os: ubuntu-18.04}
+#          - {std: 14, cxx: clang++-10, bt: Debug  , bitlinks: shared64, os: ubuntu-18.04}
+#          - {std: 14, cxx: clang++-10, bt: Release, bitlinks: shared64, os: ubuntu-18.04}
+#          - {std: 17, cxx: clang++-10, bt: Debug  , bitlinks: shared64, os: ubuntu-18.04}
+#          - {std: 17, cxx: clang++-10, bt: Release, bitlinks: shared64, os: ubuntu-18.04}
+#          - {std: 20, cxx: clang++-10, bt: Debug  , bitlinks: shared64, os: ubuntu-18.04}
+#          - {std: 20, cxx: clang++-10, bt: Release, bitlinks: shared64, os: ubuntu-18.04}
+#    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
+#    steps:
+#      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
+#      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
+#      - {name: show info, run: source .github/setenv.sh && c4_show_info}
+#      - name: shared64-configure---------------------------------------------------
+#        run: source .github/setenv.sh && c4_cfg_test shared64
+#      - {name: shared64-build, run: source .github/setenv.sh && c4_build_test shared64}
+#      - {name: clang-tidy, run: cmake "-DCMAKE_CXX_CLANG_TIDY=/usr/bin/clang-tidy-3.9;-checks=*" ../path/to/source}
+#      - {name: cppcheck, run: cmake "-DCMAKE_CXX_CPPCHECK=/usr/bin/cppcheck;--std=c++11" ../path/to/source}
+#      - {name: cpplint, run: cmake "-DCMAKE_CXX_CPPLINT=/usr/local/bin/cpplint;--linelength=179" ..}
+#      - {name: include-what-you-use, run: cmake "-DCMAKE_CXX_INCLUDE_WHAT_YOU_USE=/usr/bin/iwyu;--transitive_includes_only" ..}
+#      - {name: link-what-you-use, run: cmake -DCMAKE_LINK_WHAT_YOU_USE=TRUE ..}
diff --git a/.github/workflows/clang_tidy.yml b/.github/workflows/clang_tidy.yml
new file mode 100644
index 00000000..f4f78b34
--- /dev/null
+++ b/.github/workflows/clang_tidy.yml
@@ -0,0 +1,97 @@
+name: clang_tidy
+
+defaults:
+  #if: "!contains(github.event.head_commit.message, 'skip ci')"  # SKIP
+  run:
+    # Use a bash shell so we can use the same syntax for environment variable
+    # access regardless of the host operating system
+    shell: bash -e -x {0}
+
+on:
+  # https://github.community/t/how-to-trigger-an-action-on-push-or-pull-request-but-not-both/16662
+  workflow_dispatch:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
+
+env:
+  PROJ_PFX_TARGET: c4core-
+  PROJ_PFX_CMAKE: C4CORE_
+  CMAKE_FLAGS:
+  NUM_JOBS_BUILD: # 4
+
+
+# ubuntu-20.04:
+#   # https://github.com/actions/virtual-environments/blob/main/images/linux/Ubuntu2004-README.md
+#   gcc: 7.5.0, 8.4.0, 9.3.0, 10.2.0
+#   clang: 8.0.1, 9.0.1, 10.0.0
+# ubuntu-18.04:
+#   # https://github.com/actions/virtual-environments/blob/main/images/linux/Ubuntu1804-README.md
+#   gcc: 7.5.0, 8.4.0, 9.3.0, 10.1.0
+#   clang: 6.0.0, 8.0.0, 9.0.0
+# macos-11.0: macOS Big Sur 11.0
+#   # https://github.com/actions/virtual-environments/blob/main/images/macos/macos-11.0-Readme.md
+#   Xcode 12.1 11.7
+#   clang/LLVM 10.0.1
+#   gcc-8 gcc-9
+# macos-10.15: macOS Catalina 10.15
+#   # https://github.com/actions/virtual-environments/blob/main/images/macos/macos-10.15-Readme.md
+#   Xcode 12.1 11.7
+#   clang/LLVM 11.0.0
+#   gcc-8 gcc-9
+# windows-2019:
+#   # https://github.com/actions/virtual-environments/blob/main/images/win/Windows2019-Readme.md
+#   vs2019
+# windows-2016:
+#   # https://github.com/actions/virtual-environments/blob/main/images/win/Windows2016-Readme.md
+#   vs2017
+
+jobs:
+
+  #----------------------------------------------------------------------------
+  clang_tidy:
+    name: clang_tidy/c++${{matrix.std}}/${{matrix.bt}}
+    continue-on-error: true
+    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
+    runs-on: ${{matrix.os}}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          # clang tidy takes a long time, so don't do multiple bits/linktypes
+          - {std: 11, cxx: clang++-9, bt: Debug             , lint: clang-tidy, bitlinks: shared64, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-9, bt: Debug             , lint: clang-tidy, bitlinks: shared32, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-9, bt: Debug             , lint: clang-tidy, bitlinks: static64, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-9, bt: Debug             , lint: clang-tidy, bitlinks: static32, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-9, bt: ReleaseWithDebInfo, lint: clang-tidy, bitlinks: shared64, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-9, bt: ReleaseWithDebInfo, lint: clang-tidy, bitlinks: shared32, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-9, bt: ReleaseWithDebInfo, lint: clang-tidy, bitlinks: static64, os: ubuntu-18.04}
+          - {std: 11, cxx: clang++-9, bt: ReleaseWithDebInfo, lint: clang-tidy, bitlinks: static32, os: ubuntu-18.04}
+    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
+    steps:
+      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
+      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
+      - {name: show info, run: source .github/setenv.sh && c4_show_info}
+      - name: shared64-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared64
+      - {name: shared64-build, run: source .github/setenv.sh && c4_build_test shared64}
+      - {name: shared64-run, run: source .github/setenv.sh && c4_run_test shared64}
+      - {name: shared64-pack, run: source .github/setenv.sh && c4_package shared64}
+      - name: static64-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static64
+      - {name: static64-build, run: source .github/setenv.sh && c4_build_test static64}
+      - {name: static64-run, run: source .github/setenv.sh && c4_run_test static64}
+      - {name: static64-pack, run: source .github/setenv.sh && c4_package static64}
+      - name: static32-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static32
+      - {name: static32-build, run: source .github/setenv.sh && c4_build_test static32}
+      - {name: static32-run, run: source .github/setenv.sh && c4_run_test static32}
+      - {name: static32-pack, run: source .github/setenv.sh && c4_package static32}
+      - name: shared32-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared32
+      - {name: shared32-build, run: source .github/setenv.sh && c4_build_test shared32}
+      - {name: shared32-run, run: source .github/setenv.sh && c4_run_test shared32}
+      - {name: shared32-pack, run: source .github/setenv.sh && c4_package shared32}
diff --git a/.github/workflows/gcc.yml b/.github/workflows/gcc.yml
new file mode 100644
index 00000000..2d5a49ff
--- /dev/null
+++ b/.github/workflows/gcc.yml
@@ -0,0 +1,181 @@
+name: gcc
+
+defaults:
+  #if: "!contains(github.event.head_commit.message, 'skip ci')"  # SKIP
+  run:
+    # Use a bash shell so we can use the same syntax for environment variable
+    # access regardless of the host operating system
+    shell: bash -e -x {0}
+
+on:
+  # https://github.community/t/how-to-trigger-an-action-on-push-or-pull-request-but-not-both/16662
+  workflow_dispatch:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
+
+env:
+  PROJ_PFX_TARGET: c4core-
+  PROJ_PFX_CMAKE: C4CORE_
+  CMAKE_FLAGS:
+  NUM_JOBS_BUILD: # 4
+
+
+# ubuntu-20.04:
+#   # https://github.com/actions/virtual-environments/blob/main/images/linux/Ubuntu2004-README.md
+#   gcc: 7.5.0, 8.4.0, 9.3.0, 10.2.0
+#   clang: 8.0.1, 9.0.1, 10.0.0
+# ubuntu-18.04:
+#   # https://github.com/actions/virtual-environments/blob/main/images/linux/Ubuntu1804-README.md
+#   gcc: 7.5.0, 8.4.0, 9.3.0, 10.1.0
+#   clang: 6.0.0, 8.0.0, 9.0.0
+# macos-11.0: macOS Big Sur 11.0
+#   # https://github.com/actions/virtual-environments/blob/main/images/macos/macos-11.0-Readme.md
+#   Xcode 12.1 11.7
+#   clang/LLVM 10.0.1
+#   gcc-8 gcc-9
+# macos-10.15: macOS Catalina 10.15
+#   # https://github.com/actions/virtual-environments/blob/main/images/macos/macos-10.15-Readme.md
+#   Xcode 12.1 11.7
+#   clang/LLVM 11.0.0
+#   gcc-8 gcc-9
+# windows-2019:
+#   # https://github.com/actions/virtual-environments/blob/main/images/win/Windows2019-Readme.md
+#   vs2019
+# windows-2016:
+#   # https://github.com/actions/virtual-environments/blob/main/images/win/Windows2016-Readme.md
+#   vs2017
+
+jobs:
+
+  #----------------------------------------------------------------------------
+  gcc_canary:
+    name: gcc_canary/${{matrix.cxx}}/c++${{matrix.std}}/${{matrix.bt}}
+    continue-on-error: true
+    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
+    runs-on: ${{matrix.os}}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - {std: 11, cxx: g++-7      , bt: Debug  , os: ubuntu-18.04, bitlinks: shared64 static32}
+          - {std: 11, cxx: g++-7      , bt: Release, os: ubuntu-18.04, bitlinks: shared64 static32}
+          - {std: 20, cxx: g++-10     , bt: Debug  , os: ubuntu-18.04, bitlinks: shared64 static32}
+          - {std: 20, cxx: g++-10     , bt: Release, os: ubuntu-18.04, bitlinks: shared64 static32}
+          - {std: 11, cxx: g++-5      , bt: Debug  , os: ubuntu-18.04, bitlinks: shared64 static32}
+          - {std: 11, cxx: g++-5      , bt: Release, os: ubuntu-18.04, bitlinks: shared64 static32}
+          - {std: 11, cxx: g++-4.8    , bt: Debug,   os: ubuntu-18.04, bitlinks: shared64 static32}
+          - {std: 11, cxx: g++-4.8    , bt: Release, os: ubuntu-18.04, bitlinks: shared64 static32}
+    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
+    steps:
+      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
+      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
+      - {name: show info, run: source .github/setenv.sh && c4_show_info}
+      - name: shared64-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared64
+      - {name: shared64-build, run: source .github/setenv.sh && c4_build_test shared64}
+      - {name: shared64-run, run: source .github/setenv.sh && c4_run_test shared64}
+      - {name: shared64-pack, run: source .github/setenv.sh && c4_package shared64}
+      - name: static64-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static64
+      - {name: static64-build, run: source .github/setenv.sh && c4_build_test static64}
+      - {name: static64-run, run: source .github/setenv.sh && c4_run_test static64}
+      - {name: static64-pack, run: source .github/setenv.sh && c4_package static64}
+      - name: static32-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static32
+      - {name: static32-build, run: source .github/setenv.sh && c4_build_test static32}
+      - {name: static32-run, run: source .github/setenv.sh && c4_run_test static32}
+      - {name: static32-pack, run: source .github/setenv.sh && c4_package static32}
+      - name: shared32-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared32
+      - {name: shared32-build, run: source .github/setenv.sh && c4_build_test shared32}
+      - {name: shared32-run, run: source .github/setenv.sh && c4_run_test shared32}
+      - {name: shared32-pack, run: source .github/setenv.sh && c4_package shared32}
+
+  #----------------------------------------------------------------------------
+  gcc_extended:
+    name: gcc_extended/${{matrix.cxx}}/c++${{matrix.std}}/${{matrix.bt}}/vg${{matrix.vg}}
+    continue-on-error: true
+    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
+    runs-on: ${{matrix.os}}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          #                                     VALGRIND
+          - {std: 11, cxx: g++-10, bt: Debug  , vg: ON, os: ubuntu-18.04}
+          - {std: 11, cxx: g++-10, bt: Release, vg: ON, os: ubuntu-18.04}
+          - {std: 14, cxx: g++-10, bt: Debug  , vg: ON, os: ubuntu-18.04}
+          - {std: 14, cxx: g++-10, bt: Release, vg: ON, os: ubuntu-18.04}
+          - {std: 17, cxx: g++-10, bt: Debug  , vg: ON, os: ubuntu-18.04}
+          - {std: 17, cxx: g++-10, bt: Release, vg: ON, os: ubuntu-18.04}
+          - {std: 20, cxx: g++-10, bt: Debug  , vg: ON, os: ubuntu-18.04}
+          - {std: 20, cxx: g++-10, bt: Release, vg: ON, os: ubuntu-18.04}
+          #
+          - {std: 11, cxx: g++-9, bt: Debug  , os: ubuntu-18.04}
+          - {std: 11, cxx: g++-9, bt: Release, os: ubuntu-18.04}
+          - {std: 11, cxx: g++-8, bt: Debug  , os: ubuntu-18.04}
+          - {std: 11, cxx: g++-8, bt: Release, os: ubuntu-18.04}
+          - {std: 11, cxx: g++-7, bt: Debug  , os: ubuntu-18.04}
+          - {std: 11, cxx: g++-7, bt: Release, os: ubuntu-18.04}
+          - {std: 11, cxx: g++-6, bt: Debug  , os: ubuntu-18.04}
+          - {std: 11, cxx: g++-6, bt: Release, os: ubuntu-18.04}
+          - {std: 11, cxx: g++-5, bt: Debug  , os: ubuntu-18.04}
+          - {std: 11, cxx: g++-5, bt: Release, os: ubuntu-18.04}
+          - {std: 11, cxx: g++-4.8, bt: Debug, os: ubuntu-18.04}
+          - {std: 11, cxx: g++-4.8, bt: Release, os: ubuntu-18.04}
+    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
+    steps:
+      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
+      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
+      - {name: show info, run: source .github/setenv.sh && c4_show_info}
+      - name: shared64-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared64
+      - {name: shared64-build, run: source .github/setenv.sh && c4_build_test shared64}
+      - {name: shared64-run, run: source .github/setenv.sh && c4_run_test shared64}
+      - {name: shared64-pack, run: source .github/setenv.sh && c4_package shared64}
+      - name: static64-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static64
+      - {name: static64-build, run: source .github/setenv.sh && c4_build_test static64}
+      - {name: static64-run, run: source .github/setenv.sh && c4_run_test static64}
+      - {name: static64-pack, run: source .github/setenv.sh && c4_package static64}
+      - name: static32-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static32
+      - {name: static32-build, run: source .github/setenv.sh && c4_build_test static32}
+      - {name: static32-run, run: source .github/setenv.sh && c4_run_test static32}
+      - {name: static32-pack, run: source .github/setenv.sh && c4_package static32}
+      - name: shared32-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared32
+      - {name: shared32-build, run: source .github/setenv.sh && c4_build_test shared32}
+      - {name: shared32-run, run: source .github/setenv.sh && c4_run_test shared32}
+      - {name: shared32-pack, run: source .github/setenv.sh && c4_package shared32}
+
+  #----------------------------------------------------------------------------
+  arm:
+    continue-on-error: true
+    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
+    runs-on: ${{matrix.os}}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          # these jobs take much longer, so run only one bitlink pair per job to profit from parallelism
+          - {std: 11, bt: Debug  , toolchain: cmake/Toolchain-Arm-ubuntu.cmake, cxx: arm-linux-gnueabihf-gcc, os: ubuntu-18.04}
+          - {std: 11, bt: Release, toolchain: cmake/Toolchain-Arm-ubuntu.cmake, cxx: arm-linux-gnueabihf-gcc, os: ubuntu-18.04}
+          - {std: 14, bt: Debug  , toolchain: cmake/Toolchain-Arm-ubuntu.cmake, cxx: arm-linux-gnueabihf-gcc, os: ubuntu-18.04}
+          - {std: 14, bt: Release, toolchain: cmake/Toolchain-Arm-ubuntu.cmake, cxx: arm-linux-gnueabihf-gcc, os: ubuntu-18.04}
+          - {std: 17, bt: Debug  , toolchain: cmake/Toolchain-Arm-ubuntu.cmake, cxx: arm-linux-gnueabihf-gcc, os: ubuntu-18.04}
+          - {std: 17, bt: Release, toolchain: cmake/Toolchain-Arm-ubuntu.cmake, cxx: arm-linux-gnueabihf-gcc, os: ubuntu-18.04}
+    env: {TOOLCHAIN: "${{matrix.toolchain}}", STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
+    steps:
+      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
+      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
+      - {name: show info, run: source .github/setenv.sh && c4_show_info}
+      - name: configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test arm
+      - {name: build, run: source .github/setenv.sh && c4_build_test arm}
+      - {name: run, run: source .github/setenv.sh && c4_run_test arm}
+      - {name: pack, run: source .github/setenv.sh && c4_package arm}
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
deleted file mode 100644
index 17c066d1..00000000
--- a/.github/workflows/test.yml
+++ /dev/null
@@ -1,452 +0,0 @@
-name: test
-
-defaults:
-  #if: "!contains(github.event.head_commit.message, 'skip ci')"  # SKIP
-  run:
-    # Use a bash shell so we can use the same syntax for environment variable
-    # access regardless of the host operating system
-    shell: bash -e -x {0}
-
-on:
-  # https://github.community/t/how-to-trigger-an-action-on-push-or-pull-request-but-not-both/16662
-  workflow_dispatch:
-  push:
-    branches:
-    - master
-  pull_request:
-    branches:
-    - master
-
-env:
-  PROJ_PFX_TARGET: c4core-
-  PROJ_PFX_CMAKE: C4CORE_
-  CMAKE_FLAGS:
-  NUM_JOBS_BUILD: # 4
-
-
-# ubuntu-20.04:
-#   # https://github.com/actions/virtual-environments/blob/main/images/linux/Ubuntu2004-README.md
-#   gcc: 7.5.0, 8.4.0, 9.3.0, 10.2.0
-#   clang: 8.0.1, 9.0.1, 10.0.0
-# ubuntu-18.04:
-#   # https://github.com/actions/virtual-environments/blob/main/images/linux/Ubuntu1804-README.md
-#   gcc: 7.5.0, 8.4.0, 9.3.0, 10.1.0
-#   clang: 6.0.0, 8.0.0, 9.0.0
-# macos-11.0: macOS Big Sur 11.0
-#   # https://github.com/actions/virtual-environments/blob/main/images/macos/macos-11.0-Readme.md
-#   Xcode 12.1 11.7
-#   clang/LLVM 10.0.1
-#   gcc-8 gcc-9
-# macos-10.15: macOS Catalina 10.15
-#   # https://github.com/actions/virtual-environments/blob/main/images/macos/macos-10.15-Readme.md
-#   Xcode 12.1 11.7
-#   clang/LLVM 11.0.0
-#   gcc-8 gcc-9
-# windows-2019:
-#   # https://github.com/actions/virtual-environments/blob/main/images/win/Windows2019-Readme.md
-#   vs2019
-# windows-2016:
-#   # https://github.com/actions/virtual-environments/blob/main/images/win/Windows2016-Readme.md
-#   vs2017
-
-jobs:
-
-  #----------------------------------------------------------------------------
-  windows:
-    name: win/${{matrix.cxx}}/c++${{matrix.std}}/${{matrix.bt}}
-    continue-on-error: true
-    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
-    runs-on: ${{matrix.os}}
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - {std: 11, cxx: vs2017, bt: Debug  , os: windows-2016, bitlinks: shared64 static32}
-          - {std: 11, cxx: vs2017, bt: Release, os: windows-2016, bitlinks: shared64 static32}
-          - {std: 14, cxx: vs2017, bt: Debug  , os: windows-2016, bitlinks: shared64 static32}
-          - {std: 14, cxx: vs2017, bt: Release, os: windows-2016, bitlinks: shared64 static32}
-          - {std: 11, cxx: vs2019, bt: Debug  , os: windows-2019, bitlinks: shared64 static32}
-          - {std: 11, cxx: vs2019, bt: Release, os: windows-2019, bitlinks: shared64 static32}
-          - {std: 14, cxx: vs2019, bt: Debug  , os: windows-2019, bitlinks: shared64 static32}
-          - {std: 14, cxx: vs2019, bt: Release, os: windows-2019, bitlinks: shared64 static32}
-          - {std: 17, cxx: vs2019, bt: Debug  , os: windows-2019, bitlinks: shared64 static32}
-          - {std: 17, cxx: vs2019, bt: Release, os: windows-2019, bitlinks: shared64 static32}
-          - {std: 20, cxx: vs2019, bt: Debug  , os: windows-2019, bitlinks: shared64 static32}
-          - {std: 20, cxx: vs2019, bt: Release, os: windows-2019, bitlinks: shared64 static32}
-    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
-    steps:
-      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
-      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
-      - {name: show info, run: source .github/setenv.sh && c4_show_info}
-      - name: shared64-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test shared64
-      - {name: shared64-build, run: source .github/setenv.sh && c4_build_test shared64}
-      - {name: shared64-run, run: source .github/setenv.sh && c4_run_test shared64}
-      - {name: shared64-pack, run: source .github/setenv.sh && c4_package shared64}
-      - name: static64-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test static64
-      - {name: static64-build, run: source .github/setenv.sh && c4_build_test static64}
-      - {name: static64-run, run: source .github/setenv.sh && c4_run_test static64}
-      - {name: static64-pack, run: source .github/setenv.sh && c4_package static64}
-      - name: shared32-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test shared32
-      - {name: shared32-build, run: source .github/setenv.sh && c4_build_test shared32}
-      - {name: shared32-run, run: source .github/setenv.sh && c4_run_test shared32}
-      - {name: shared32-pack, run: source .github/setenv.sh && c4_package shared32}
-      - name: static32-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test static32
-      - {name: static32-build, run: source .github/setenv.sh && c4_build_test static32}
-      - {name: static32-run, run: source .github/setenv.sh && c4_run_test static32}
-      - {name: static32-pack, run: source .github/setenv.sh && c4_package static32}
-
-  #----------------------------------------------------------------------------
-  gcc_canary:
-    name: gcc_canary/${{matrix.cxx}}/c++${{matrix.std}}/${{matrix.bt}}
-    continue-on-error: true
-    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
-    runs-on: ${{matrix.os}}
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - {std: 11, cxx: g++-7      , bt: Debug  , os: ubuntu-18.04, bitlinks: shared64 static32}
-          - {std: 11, cxx: g++-7      , bt: Release, os: ubuntu-18.04, bitlinks: shared64 static32}
-          - {std: 20, cxx: g++-10     , bt: Debug  , os: ubuntu-18.04, bitlinks: shared64 static32}
-          - {std: 20, cxx: g++-10     , bt: Release, os: ubuntu-18.04, bitlinks: shared64 static32}
-          - {std: 11, cxx: g++-5      , bt: Debug  , os: ubuntu-18.04, bitlinks: shared64 static32}
-          - {std: 11, cxx: g++-5      , bt: Release, os: ubuntu-18.04, bitlinks: shared64 static32}
-          - {std: 11, cxx: g++-4.8    , bt: Debug,   os: ubuntu-18.04, bitlinks: shared64 static32}
-          - {std: 11, cxx: g++-4.8    , bt: Release, os: ubuntu-18.04, bitlinks: shared64 static32}
-    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
-    steps:
-      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
-      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
-      - {name: show info, run: source .github/setenv.sh && c4_show_info}
-      - name: shared64-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test shared64
-      - {name: shared64-build, run: source .github/setenv.sh && c4_build_test shared64}
-      - {name: shared64-run, run: source .github/setenv.sh && c4_run_test shared64}
-      - {name: shared64-pack, run: source .github/setenv.sh && c4_package shared64}
-      - name: static64-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test static64
-      - {name: static64-build, run: source .github/setenv.sh && c4_build_test static64}
-      - {name: static64-run, run: source .github/setenv.sh && c4_run_test static64}
-      - {name: static64-pack, run: source .github/setenv.sh && c4_package static64}
-      - name: static32-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test static32
-      - {name: static32-build, run: source .github/setenv.sh && c4_build_test static32}
-      - {name: static32-run, run: source .github/setenv.sh && c4_run_test static32}
-      - {name: static32-pack, run: source .github/setenv.sh && c4_package static32}
-      - name: shared32-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test shared32
-      - {name: shared32-build, run: source .github/setenv.sh && c4_build_test shared32}
-      - {name: shared32-run, run: source .github/setenv.sh && c4_run_test shared32}
-      - {name: shared32-pack, run: source .github/setenv.sh && c4_package shared32}
-
-  #----------------------------------------------------------------------------
-  clang_canary:
-    name: clang_canary/${{matrix.cxx}}/c++${{matrix.std}}/${{matrix.bt}}
-    continue-on-error: true
-    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
-    runs-on: ${{matrix.os}}
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - {std: 20, cxx: clang++-10 , bt: Debug  , os: ubuntu-18.04, bitlinks: shared64 static32}
-          - {std: 20, cxx: clang++-10 , bt: Release, os: ubuntu-18.04, bitlinks: shared64 static32}
-          - {std: 11, cxx: clang++-6.0, bt: Debug  , os: ubuntu-18.04, bitlinks: shared64 static32}
-          - {std: 11, cxx: clang++-6.0, bt: Release, os: ubuntu-18.04, bitlinks: shared64 static32}
-    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
-    steps:
-      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
-      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
-      - {name: show info, run: source .github/setenv.sh && c4_show_info}
-      - name: shared64-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test shared64
-      - {name: shared64-build, run: source .github/setenv.sh && c4_build_test shared64}
-      - {name: shared64-run, run: source .github/setenv.sh && c4_run_test shared64}
-      - {name: shared64-pack, run: source .github/setenv.sh && c4_package shared64}
-      - name: static64-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test static64
-      - {name: static64-build, run: source .github/setenv.sh && c4_build_test static64}
-      - {name: static64-run, run: source .github/setenv.sh && c4_run_test static64}
-      - {name: static64-pack, run: source .github/setenv.sh && c4_package static64}
-      - name: static32-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test static32
-      - {name: static32-build, run: source .github/setenv.sh && c4_build_test static32}
-      - {name: static32-run, run: source .github/setenv.sh && c4_run_test static32}
-      - {name: static32-pack, run: source .github/setenv.sh && c4_package static32}
-      - name: shared32-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test shared32
-      - {name: shared32-build, run: source .github/setenv.sh && c4_build_test shared32}
-      - {name: shared32-run, run: source .github/setenv.sh && c4_run_test shared32}
-      - {name: shared32-pack, run: source .github/setenv.sh && c4_package shared32}
-
-  #----------------------------------------------------------------------------
-  clang_tidy:
-    name: clang_tidy/c++${{matrix.std}}/${{matrix.bt}}
-    continue-on-error: true
-    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
-    runs-on: ${{matrix.os}}
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          # clang tidy takes a long time, so don't do multiple bits/linktypes
-          - {std: 11, cxx: clang++-9, bt: Debug             , lint: clang-tidy, bitlinks: shared64, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-9, bt: Debug             , lint: clang-tidy, bitlinks: shared32, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-9, bt: Debug             , lint: clang-tidy, bitlinks: static64, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-9, bt: Debug             , lint: clang-tidy, bitlinks: static32, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-9, bt: ReleaseWithDebInfo, lint: clang-tidy, bitlinks: shared64, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-9, bt: ReleaseWithDebInfo, lint: clang-tidy, bitlinks: shared32, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-9, bt: ReleaseWithDebInfo, lint: clang-tidy, bitlinks: static64, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-9, bt: ReleaseWithDebInfo, lint: clang-tidy, bitlinks: static32, os: ubuntu-18.04}
-    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
-    steps:
-      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
-      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
-      - {name: show info, run: source .github/setenv.sh && c4_show_info}
-      - name: shared64-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test shared64
-      - {name: shared64-build, run: source .github/setenv.sh && c4_build_test shared64}
-      - {name: shared64-run, run: source .github/setenv.sh && c4_run_test shared64}
-      - {name: shared64-pack, run: source .github/setenv.sh && c4_package shared64}
-      - name: static64-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test static64
-      - {name: static64-build, run: source .github/setenv.sh && c4_build_test static64}
-      - {name: static64-run, run: source .github/setenv.sh && c4_run_test static64}
-      - {name: static64-pack, run: source .github/setenv.sh && c4_package static64}
-      - name: static32-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test static32
-      - {name: static32-build, run: source .github/setenv.sh && c4_build_test static32}
-      - {name: static32-run, run: source .github/setenv.sh && c4_run_test static32}
-      - {name: static32-pack, run: source .github/setenv.sh && c4_package static32}
-      - name: shared32-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test shared32
-      - {name: shared32-build, run: source .github/setenv.sh && c4_build_test shared32}
-      - {name: shared32-run, run: source .github/setenv.sh && c4_run_test shared32}
-      - {name: shared32-pack, run: source .github/setenv.sh && c4_package shared32}
-
-  #----------------------------------------------------------------------------
-  gcc_extended:
-    name: gcc_extended/${{matrix.cxx}}/c++${{matrix.std}}/${{matrix.bt}}/vg${{matrix.vg}}
-    continue-on-error: true
-    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
-    runs-on: ${{matrix.os}}
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          #                                     VALGRIND
-          - {std: 11, cxx: g++-10, bt: Debug  , vg: ON, os: ubuntu-18.04}
-          - {std: 11, cxx: g++-10, bt: Release, vg: ON, os: ubuntu-18.04}
-          - {std: 14, cxx: g++-10, bt: Debug  , vg: ON, os: ubuntu-18.04}
-          - {std: 14, cxx: g++-10, bt: Release, vg: ON, os: ubuntu-18.04}
-          - {std: 17, cxx: g++-10, bt: Debug  , vg: ON, os: ubuntu-18.04}
-          - {std: 17, cxx: g++-10, bt: Release, vg: ON, os: ubuntu-18.04}
-          - {std: 20, cxx: g++-10, bt: Debug  , vg: ON, os: ubuntu-18.04}
-          - {std: 20, cxx: g++-10, bt: Release, vg: ON, os: ubuntu-18.04}
-          #
-          - {std: 11, cxx: g++-9, bt: Debug  , os: ubuntu-18.04}
-          - {std: 11, cxx: g++-9, bt: Release, os: ubuntu-18.04}
-          - {std: 11, cxx: g++-8, bt: Debug  , os: ubuntu-18.04}
-          - {std: 11, cxx: g++-8, bt: Release, os: ubuntu-18.04}
-          - {std: 11, cxx: g++-7, bt: Debug  , os: ubuntu-18.04}
-          - {std: 11, cxx: g++-7, bt: Release, os: ubuntu-18.04}
-          - {std: 11, cxx: g++-6, bt: Debug  , os: ubuntu-18.04}
-          - {std: 11, cxx: g++-6, bt: Release, os: ubuntu-18.04}
-          - {std: 11, cxx: g++-5, bt: Debug  , os: ubuntu-18.04}
-          - {std: 11, cxx: g++-5, bt: Release, os: ubuntu-18.04}
-          - {std: 11, cxx: g++-4.8, bt: Debug, os: ubuntu-18.04}
-          - {std: 11, cxx: g++-4.8, bt: Release, os: ubuntu-18.04}
-    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
-    steps:
-      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
-      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
-      - {name: show info, run: source .github/setenv.sh && c4_show_info}
-      - name: shared64-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test shared64
-      - {name: shared64-build, run: source .github/setenv.sh && c4_build_test shared64}
-      - {name: shared64-run, run: source .github/setenv.sh && c4_run_test shared64}
-      - {name: shared64-pack, run: source .github/setenv.sh && c4_package shared64}
-      - name: static64-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test static64
-      - {name: static64-build, run: source .github/setenv.sh && c4_build_test static64}
-      - {name: static64-run, run: source .github/setenv.sh && c4_run_test static64}
-      - {name: static64-pack, run: source .github/setenv.sh && c4_package static64}
-      - name: static32-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test static32
-      - {name: static32-build, run: source .github/setenv.sh && c4_build_test static32}
-      - {name: static32-run, run: source .github/setenv.sh && c4_run_test static32}
-      - {name: static32-pack, run: source .github/setenv.sh && c4_package static32}
-      - name: shared32-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test shared32
-      - {name: shared32-build, run: source .github/setenv.sh && c4_build_test shared32}
-      - {name: shared32-run, run: source .github/setenv.sh && c4_run_test shared32}
-      - {name: shared32-pack, run: source .github/setenv.sh && c4_package shared32}
-
-  #----------------------------------------------------------------------------
-  clang_extended:
-    name: clang_extended/${{matrix.cxx}}/c++${{matrix.std}}/${{matrix.bt}}/vg${{matrix.vg}}
-    continue-on-error: true
-    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
-    runs-on: ${{matrix.os}}
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - {std: 20, cxx: clang++-10 , bt: Debug  , vg: on, os: ubuntu-18.04}
-          - {std: 20, cxx: clang++-10 , bt: Release, vg: on, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-9  , bt: Debug  , vg: on, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-9  , bt: Release, vg: on, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-8  , bt: Debug  , vg: on, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-8  , bt: Release, vg: on, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-7  , bt: Debug  , vg: on, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-7  , bt: Release, vg: on, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-6.0, bt: Debug  , vg: on, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-6.0, bt: Release, vg: on, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-5.0, bt: Debug  , vg: on, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-5.0, bt: Release, vg: on, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-4.0, bt: Debug  , vg: on, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-4.0, bt: Release, vg: on, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-3.9, bt: Debug  , vg: on, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-3.9, bt: Release, vg: on, os: ubuntu-18.04}
-    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
-    steps:
-      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
-      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
-      - {name: show info, run: source .github/setenv.sh && c4_show_info}
-      - name: shared64-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test shared64
-      - {name: shared64-build, run: source .github/setenv.sh && c4_build_test shared64}
-      - {name: shared64-run, run: source .github/setenv.sh && c4_run_test shared64}
-      - {name: shared64-pack, run: source .github/setenv.sh && c4_package shared64}
-      - name: static64-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test static64
-      - {name: static64-build, run: source .github/setenv.sh && c4_build_test static64}
-      - {name: static64-run, run: source .github/setenv.sh && c4_run_test static64}
-      - {name: static64-pack, run: source .github/setenv.sh && c4_package static64}
-      - name: static32-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test static32
-      - {name: static32-build, run: source .github/setenv.sh && c4_build_test static32}
-      - {name: static32-run, run: source .github/setenv.sh && c4_run_test static32}
-      - {name: static32-pack, run: source .github/setenv.sh && c4_package static32}
-      - name: shared32-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test shared32
-      - {name: shared32-build, run: source .github/setenv.sh && c4_build_test shared32}
-      - {name: shared32-run, run: source .github/setenv.sh && c4_run_test shared32}
-      - {name: shared32-pack, run: source .github/setenv.sh && c4_package shared32}
-
-  #----------------------------------------------------------------------------
-  clang_sanitize:
-    name: clang_sanitize/c++${{matrix.std}}/${{matrix.bt}}/vg${{matrix.vg}}
-    continue-on-error: true
-    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
-    runs-on: ${{matrix.os}}
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          # these jobs take much longer, so run only one bitlink pair per job to profit from parallelism
-          - {std: 11, cxx: clang++-10 , bt: Debug  , vg: ON, san: ALL, bitlinks: shared64 static64, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-10 , bt: Debug  , vg: ON, san: ALL, bitlinks: shared32 static32, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-10 , bt: Release, vg: ON, san: ALL, bitlinks: shared64 static64, os: ubuntu-18.04}
-          - {std: 11, cxx: clang++-10 , bt: Release, vg: ON, san: ALL, bitlinks: shared32 static32, os: ubuntu-18.04}
-          - {std: 14, cxx: clang++-10 , bt: Debug  , vg: ON, san: ALL, bitlinks: shared64 static64, os: ubuntu-18.04}
-          - {std: 14, cxx: clang++-10 , bt: Debug  , vg: ON, san: ALL, bitlinks: shared32 static32, os: ubuntu-18.04}
-          - {std: 14, cxx: clang++-10 , bt: Release, vg: ON, san: ALL, bitlinks: shared64 static64, os: ubuntu-18.04}
-          - {std: 14, cxx: clang++-10 , bt: Release, vg: ON, san: ALL, bitlinks: shared32 static32, os: ubuntu-18.04}
-          - {std: 17, cxx: clang++-10 , bt: Debug  , vg: ON, san: ALL, bitlinks: shared64 static64, os: ubuntu-18.04}
-          - {std: 17, cxx: clang++-10 , bt: Debug  , vg: ON, san: ALL, bitlinks: shared32 static32, os: ubuntu-18.04}
-          - {std: 17, cxx: clang++-10 , bt: Release, vg: ON, san: ALL, bitlinks: shared64 static64, os: ubuntu-18.04}
-          - {std: 17, cxx: clang++-10 , bt: Release, vg: ON, san: ALL, bitlinks: shared32 static32, os: ubuntu-18.04}
-          - {std: 20, cxx: clang++-10 , bt: Debug  , vg: ON, san: ALL, bitlinks: shared64 static64, os: ubuntu-18.04}
-          - {std: 20, cxx: clang++-10 , bt: Debug  , vg: ON, san: ALL, bitlinks: shared32 static32, os: ubuntu-18.04}
-          - {std: 20, cxx: clang++-10 , bt: Release, vg: ON, san: ALL, bitlinks: shared64 static64, os: ubuntu-18.04}
-          - {std: 20, cxx: clang++-10 , bt: Release, vg: ON, san: ALL, bitlinks: shared32 static32, os: ubuntu-18.04}
-    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
-    steps:
-      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
-      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
-      - {name: show info, run: source .github/setenv.sh && c4_show_info}
-      - name: shared64-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test shared64
-      - {name: shared64-build, run: source .github/setenv.sh && c4_build_test shared64}
-      - {name: shared64-run, run: source .github/setenv.sh && c4_run_test shared64}
-      - {name: shared64-pack, run: source .github/setenv.sh && c4_package shared64}
-      - name: static64-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test static64
-      - {name: static64-build, run: source .github/setenv.sh && c4_build_test static64}
-      - {name: static64-run, run: source .github/setenv.sh && c4_run_test static64}
-      - {name: static64-pack, run: source .github/setenv.sh && c4_package static64}
-      - name: static32-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test static32
-      - {name: static32-build, run: source .github/setenv.sh && c4_build_test static32}
-      - {name: static32-run, run: source .github/setenv.sh && c4_run_test static32}
-      - {name: static32-pack, run: source .github/setenv.sh && c4_package static32}
-      - name: shared32-configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test shared32
-      - {name: shared32-build, run: source .github/setenv.sh && c4_build_test shared32}
-      - {name: shared32-run, run: source .github/setenv.sh && c4_run_test shared32}
-      - {name: shared32-pack, run: source .github/setenv.sh && c4_package shared32}
-
-  #----------------------------------------------------------------------------
-  arm:
-    continue-on-error: true
-    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
-    runs-on: ${{matrix.os}}
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          # these jobs take much longer, so run only one bitlink pair per job to profit from parallelism
-          - {std: 11, bt: Debug  , toolchain: cmake/Toolchain-Arm-ubuntu.cmake, cxx: arm-linux-gnueabihf-gcc, os: ubuntu-18.04}
-          - {std: 11, bt: Release, toolchain: cmake/Toolchain-Arm-ubuntu.cmake, cxx: arm-linux-gnueabihf-gcc, os: ubuntu-18.04}
-          - {std: 14, bt: Debug  , toolchain: cmake/Toolchain-Arm-ubuntu.cmake, cxx: arm-linux-gnueabihf-gcc, os: ubuntu-18.04}
-          - {std: 14, bt: Release, toolchain: cmake/Toolchain-Arm-ubuntu.cmake, cxx: arm-linux-gnueabihf-gcc, os: ubuntu-18.04}
-          - {std: 17, bt: Debug  , toolchain: cmake/Toolchain-Arm-ubuntu.cmake, cxx: arm-linux-gnueabihf-gcc, os: ubuntu-18.04}
-          - {std: 17, bt: Release, toolchain: cmake/Toolchain-Arm-ubuntu.cmake, cxx: arm-linux-gnueabihf-gcc, os: ubuntu-18.04}
-    env: {TOOLCHAIN: "${{matrix.toolchain}}", STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
-    steps:
-      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
-      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
-      - {name: show info, run: source .github/setenv.sh && c4_show_info}
-      - name: configure---------------------------------------------------
-        run: source .github/setenv.sh && c4_cfg_test arm
-      - {name: build, run: source .github/setenv.sh && c4_build_test arm}
-      - {name: run, run: source .github/setenv.sh && c4_run_test arm}
-      - {name: pack, run: source .github/setenv.sh && c4_package arm}
-
-  #----------------------------------------------------------------------------
-#  # https://blog.kitware.com/static-checks-with-cmake-cdash-iwyu-clang-tidy-lwyu-cpplint-and-cppcheck/
-#  static_analysis:
-#    continue-on-error: true
-#    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
-#    runs-on: ${{matrix.os}}
-#    strategy:
-#      fail-fast: false
-#      matrix:
-#        include:
-#          # these jobs take much longer, so run only one bitlink pair per job to profit from parallelism
-#          - {std: 11, cxx: clang++-10, bt: Debug  , bitlinks: shared64, os: ubuntu-18.04}
-#          - {std: 11, cxx: clang++-10, bt: Release, bitlinks: shared64, os: ubuntu-18.04}
-#          - {std: 14, cxx: clang++-10, bt: Debug  , bitlinks: shared64, os: ubuntu-18.04}
-#          - {std: 14, cxx: clang++-10, bt: Release, bitlinks: shared64, os: ubuntu-18.04}
-#          - {std: 17, cxx: clang++-10, bt: Debug  , bitlinks: shared64, os: ubuntu-18.04}
-#          - {std: 17, cxx: clang++-10, bt: Release, bitlinks: shared64, os: ubuntu-18.04}
-#          - {std: 20, cxx: clang++-10, bt: Debug  , bitlinks: shared64, os: ubuntu-18.04}
-#          - {std: 20, cxx: clang++-10, bt: Release, bitlinks: shared64, os: ubuntu-18.04}
-#    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
-#    steps:
-#      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
-#      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
-#      - {name: show info, run: source .github/setenv.sh && c4_show_info}
-#      - name: shared64-configure---------------------------------------------------
-#        run: source .github/setenv.sh && c4_cfg_test shared64
-#      - {name: shared64-build, run: source .github/setenv.sh && c4_build_test shared64}
-#      - {name: clang-tidy, run: cmake "-DCMAKE_CXX_CLANG_TIDY=/usr/bin/clang-tidy-3.9;-checks=*" ../path/to/source}
-#      - {name: cppcheck, run: cmake "-DCMAKE_CXX_CPPCHECK=/usr/bin/cppcheck;--std=c++11" ../path/to/source}
-#      - {name: cpplint, run: cmake "-DCMAKE_CXX_CPPLINT=/usr/local/bin/cpplint;--linelength=179" ..}
-#      - {name: include-what-you-use, run: cmake "-DCMAKE_CXX_INCLUDE_WHAT_YOU_USE=/usr/bin/iwyu;--transitive_includes_only" ..}
-#      - {name: link-what-you-use, run: cmake -DCMAKE_LINK_WHAT_YOU_USE=TRUE ..}
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
new file mode 100644
index 00000000..41295c15
--- /dev/null
+++ b/.github/workflows/windows.yml
@@ -0,0 +1,154 @@
+name: windows
+
+defaults:
+  #if: "!contains(github.event.head_commit.message, 'skip ci')"  # SKIP
+  run:
+    # Use a bash shell so we can use the same syntax for environment variable
+    # access regardless of the host operating system
+    shell: bash -e -x {0}
+
+on:
+  # https://github.community/t/how-to-trigger-an-action-on-push-or-pull-request-but-not-both/16662
+  workflow_dispatch:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
+
+env:
+  PROJ_PFX_TARGET: c4core-
+  PROJ_PFX_CMAKE: C4CORE_
+  CMAKE_FLAGS:
+  NUM_JOBS_BUILD: # 4
+
+
+# ubuntu-20.04:
+#   # https://github.com/actions/virtual-environments/blob/main/images/linux/Ubuntu2004-README.md
+#   gcc: 7.5.0, 8.4.0, 9.3.0, 10.2.0
+#   clang: 8.0.1, 9.0.1, 10.0.0
+# ubuntu-18.04:
+#   # https://github.com/actions/virtual-environments/blob/main/images/linux/Ubuntu1804-README.md
+#   gcc: 7.5.0, 8.4.0, 9.3.0, 10.1.0
+#   clang: 6.0.0, 8.0.0, 9.0.0
+# macos-11.0: macOS Big Sur 11.0
+#   # https://github.com/actions/virtual-environments/blob/main/images/macos/macos-11.0-Readme.md
+#   Xcode 12.1 11.7
+#   clang/LLVM 10.0.1
+#   gcc-8 gcc-9
+# macos-10.15: macOS Catalina 10.15
+#   # https://github.com/actions/virtual-environments/blob/main/images/macos/macos-10.15-Readme.md
+#   Xcode 12.1 11.7
+#   clang/LLVM 11.0.0
+#   gcc-8 gcc-9
+# windows-2019:
+#   # https://github.com/actions/virtual-environments/blob/main/images/win/Windows2019-Readme.md
+#   vs2019
+# windows-2016:
+#   # https://github.com/actions/virtual-environments/blob/main/images/win/Windows2016-Readme.md
+#   vs2017
+
+jobs:
+
+  #----------------------------------------------------------------------------
+  windows:
+    name: win/${{matrix.cxx}}/c++${{matrix.std}}/${{matrix.bt}}
+    continue-on-error: true
+    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
+    runs-on: ${{matrix.os}}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - {std: 11, cxx: vs2017, bt: Debug  , os: windows-2016, bitlinks: shared64 static32}
+          - {std: 11, cxx: vs2017, bt: Release, os: windows-2016, bitlinks: shared64 static32}
+          - {std: 14, cxx: vs2017, bt: Debug  , os: windows-2016, bitlinks: shared64 static32}
+          - {std: 14, cxx: vs2017, bt: Release, os: windows-2016, bitlinks: shared64 static32}
+          #
+          - {std: 11, cxx: vs2019, bt: Debug  , os: windows-2019, bitlinks: shared64 static32}
+          - {std: 11, cxx: vs2019, bt: Release, os: windows-2019, bitlinks: shared64 static32}
+          - {std: 14, cxx: vs2019, bt: Debug  , os: windows-2019, bitlinks: shared64 static32}
+          - {std: 14, cxx: vs2019, bt: Release, os: windows-2019, bitlinks: shared64 static32}
+          - {std: 17, cxx: vs2019, bt: Debug  , os: windows-2019, bitlinks: shared64 static32}
+          - {std: 17, cxx: vs2019, bt: Release, os: windows-2019, bitlinks: shared64 static32}
+          #
+          - {std: 11, cxx: vs2022, bt: Debug  , os: windows-2022, bitlinks: shared64 static32}
+          - {std: 11, cxx: vs2022, bt: Release, os: windows-2022, bitlinks: shared64 static32}
+          - {std: 14, cxx: vs2022, bt: Debug  , os: windows-2022, bitlinks: shared64 static32}
+          - {std: 14, cxx: vs2022, bt: Release, os: windows-2022, bitlinks: shared64 static32}
+          - {std: 17, cxx: vs2022, bt: Debug  , os: windows-2022, bitlinks: shared64 static32}
+          - {std: 17, cxx: vs2022, bt: Release, os: windows-2022, bitlinks: shared64 static32}
+          - {std: 20, cxx: vs2022, bt: Debug  , os: windows-2022, bitlinks: shared64 static32}
+          - {std: 20, cxx: vs2022, bt: Release, os: windows-2022, bitlinks: shared64 static32}
+    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
+    steps:
+      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
+      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
+      - {name: show info, run: source .github/setenv.sh && c4_show_info}
+      - name: shared64-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared64
+      - {name: shared64-build, run: source .github/setenv.sh && c4_build_test shared64}
+      - {name: shared64-run, run: source .github/setenv.sh && c4_run_test shared64}
+      - {name: shared64-pack, run: source .github/setenv.sh && c4_package shared64}
+      - name: static64-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static64
+      - {name: static64-build, run: source .github/setenv.sh && c4_build_test static64}
+      - {name: static64-run, run: source .github/setenv.sh && c4_run_test static64}
+      - {name: static64-pack, run: source .github/setenv.sh && c4_package static64}
+      - name: shared32-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared32
+      - {name: shared32-build, run: source .github/setenv.sh && c4_build_test shared32}
+      - {name: shared32-run, run: source .github/setenv.sh && c4_run_test shared32}
+      - {name: shared32-pack, run: source .github/setenv.sh && c4_package shared32}
+      - name: static32-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static32
+      - {name: static32-build, run: source .github/setenv.sh && c4_build_test static32}
+      - {name: static32-run, run: source .github/setenv.sh && c4_run_test static32}
+      - {name: static32-pack, run: source .github/setenv.sh && c4_package static32}
+
+  #----------------------------------------------------------------------------
+  # TODO how to run?
+  windows_arm:
+    name: win_arm/${{matrix.cxx}}/c++${{matrix.std}}/${{matrix.bt}}
+    continue-on-error: true
+    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
+    runs-on: ${{matrix.os}}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - {std: 11, cxx: vs2019, bt: Debug  , os: windows-2019, bitlinks: shared64arm static32arm}
+          - {std: 11, cxx: vs2019, bt: Release, os: windows-2019, bitlinks: shared64arm static32arm}
+          - {std: 17, cxx: vs2019, bt: Debug  , os: windows-2019, bitlinks: shared64arm static32arm}
+          - {std: 17, cxx: vs2019, bt: Release, os: windows-2019, bitlinks: shared64arm static32arm}
+          #
+          - {std: 11, cxx: vs2022, bt: Debug  , os: windows-2022, bitlinks: shared64arm static32arm}
+          - {std: 11, cxx: vs2022, bt: Release, os: windows-2022, bitlinks: shared64arm static32arm}
+          - {std: 20, cxx: vs2022, bt: Debug  , os: windows-2022, bitlinks: shared64arm static32arm}
+          - {std: 20, cxx: vs2022, bt: Release, os: windows-2022, bitlinks: shared64arm static32arm}
+    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
+    steps:
+      - {name: checkout, uses: actions/checkout@v2, with: {submodules: recursive}}
+      - {name: install requirements, run: source .github/reqs.sh && c4_install_test_requirements $OS}
+      - {name: show info, run: source .github/setenv.sh && c4_show_info}
+      - name: shared64arm-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared64arm
+      - {name: shared64arm-build, run: source .github/setenv.sh && c4_build_test shared64arm}
+      #- {name: shared64arm-run, run: source .github/setenv.sh && c4_run_test shared64arm}
+      - {name: shared64arm-pack, run: source .github/setenv.sh && c4_package shared64arm}
+      - name: static64arm-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static64arm
+      - {name: static64arm-build, run: source .github/setenv.sh && c4_build_test static64arm}
+      #- {name: static64arm-run, run: source .github/setenv.sh && c4_run_test static64arm}
+      - {name: static64arm-pack, run: source .github/setenv.sh && c4_package static64arm}
+      - name: shared32arm-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared32arm
+      - {name: shared32arm-build, run: source .github/setenv.sh && c4_build_test shared32arm}
+      #- {name: shared32arm-run, run: source .github/setenv.sh && c4_run_test shared32arm}
+      - {name: shared32arm-pack, run: source .github/setenv.sh && c4_package shared32arm}
+      - name: static32arm-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static32arm
+      - {name: static32arm-build, run: source .github/setenv.sh && c4_build_test static32arm}
+      #- {name: static32arm-run, run: source .github/setenv.sh && c4_run_test static32arm}
+      - {name: static32arm-pack, run: source .github/setenv.sh && c4_package static32arm}