Squashed 'lib/cpp-library/' changes from e3f1ba8..e3add8e
Squashed 'lib/cpp-library/' changes from e3f1ba8..e3add8e

e3add8e Fix constexpr

git-subtree-dir: lib/cpp-library
git-subtree-split: e3add8eb56777546f77d1bf6ef2866e68a59f1bb

acclimate/acclimate