They do have that rule, but not for performance reasons. The full decision is here https://google.github.io/styleguide/cppguide.html#Exceptions https://google.g

They do have that rule, but not for performance reasons. The full decision is here https://google.github.io/styleguide/cppguide.html#Exceptions https://google.github.io/styleguide/cppguide.html#Exceptions and probably worth a read but the two main take away I think is: > Because most existing C++ code at Google is not prepared to deal with exceptions, it is comparatively difficult to adopt new code that generates exceptions.