# Custom TTL (seconds)
Green: Midwest football cities
，更多细节参见新收录的资料
# Switch to unrestricted
The C++ committee’s approach — adding opt-in safety features to the language — is the exact opposite of what worked at Google. Google’s strategy says: write new code in languages where safety tools aren’t needed because safety is the default. The committee’s strategy says: keep writing new code in C++, but use these new safety tools. Google has empirical data showing their approach works. The committee has proposals.