"On their face, the benefits of using exceptions outweigh the costs, especially in new projects. However, for existing code, the introduction of exceptions h

"On their face, the benefits of using exceptions outweigh the costs, especially in new projects. However, for existing code, the introduction of exceptions has implications on all dependent code. If exceptions can be propagated beyond a new project, it also becomes problematic to integrate the new project into existing exception-free code. 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." (https://google.github.io/styleguide/cppguide.html#Exceptions) So, basically, Google forbids exceptions for historical reasons, not because of performance. But, sadly, countless companies parroted this section of Google's style guide for all the wrong reasons (mostly just cargo culting Google) leading to unfortunate fragmentation of error handling in the C++ library ecosystem.