reenable macos in CI

.github/workflows/build.yaml

@@ -66,22 +66,22 @@ jobs:
       - name: Build and test cubescript
         run: bash ./.ci/build-cs-windows
 
-#  mac:
-#    name: MacOS
-#    runs-on: macos-10.15
+  mac:
+    name: MacOS
+    runs-on: macos-10.15
 
-#    env:
-#      TARGET: 'darwin'
-#      CC: 'clang'
+    env:
+      TARGET: 'darwin'
+      CC: 'clang'
 
-#    steps:
-#      - name: Checkout
-#        uses: actions/checkout@v2
-#        with:
-#          persist-credentials: false
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          persist-credentials: false
 
-#      - name: Prepare environment
-#        run: sh ./.ci/install-env
+      - name: Prepare environment
+        run: sh ./.ci/install-env
 
-#      - name: Build and test cubescript
-#        run: sh ./.ci/build-cs
+      - name: Build and test cubescript
+        run: sh ./.ci/build-cs

README.md

@@ -107,15 +107,14 @@ The library has absolutely no dependencies other than a C++20 compiler,
 similarly there are no dependencies on system or architecture specific
 things, so it should work on any OS and any CPU.
 
-The C++20 support does not have to be complete. Right now, tested
-compilers include:
+The C++20 support does not have to be complete. These are the baselines
+(which are ensured by the CI):
 
 * GCC 10
-* Clang 11
+* Clang 10 (with libstdc++ or libc++)
 * Microsoft Visual C++ 2019
 
-Older versions of Clang may work, with no guarantees (GCC 9 does not, though,
-as it's missing features in libstdc++).
+Older versions of either of these are known not to work.
 
 You will need [Meson](https://mesonbuild.com/) to build the project. Most
 Unix-like systems have it in their package management, on Windows there is