[jeffbee]

There are other languages of course where the logging avoids this, even in libraries written by the same company that writes Go. In C++, the Abseil logging library (f.k.a. glog) will not evaluate a condition for a disabled log level.

  LOG(INFO) << WowExpensiveFunction();

This is safe when the log level is set to WARN or higher. For the same reasons, LOG_EVERY_N and LOG_FIRST_N in the same library are pretty cheap.