As for <chrono>, the link you provided also has a (short) justification behind the decision: https://chromium.googlesource.com/chromium/src/+/HEAD/styleguide/c+

As for <chrono>, the link you provided also has a (short) justification behind the decision: https://chromium.googlesource.com/chromium/src/+/HEAD/styleguide/c++/c++-features.md#date-and-time-utilities-banned https://chromium.googlesource.com/chromium/src/+/HEAD/styleg... Regarding smart pointers, not sure if you also found this: https://chromium.googlesource.com/chromium/src/+/HEAD/base/memory/README.md https://chromium.googlesource.com/chromium/src/+/HEAD/base/m...