Squashed 'libs/cli11/' content from commit dcbcb47

git-subtree-dir: libs/cli11
git-subtree-split: dcbcb4721dda5dab0a56d9faaaee50e6a30f7758

scripts/check_style.sh

@@ -0,0 +1,10 @@
+#!/usr/bin/env sh
+set -evx
+
+clang-format --version
+
+git ls-files -- '*.cpp' '*.hpp' | xargs clang-format -sort-includes -i -style=file
+
+git diff --exit-code --color
+
+set +evx