More about the check in the documentation^[0], but this basically allow for better move & copy constructor in some subtle situations that do occur in our code base (I tried to just delete those and the build fails). [0] https://clang.llvm.org/extra/clang-tidy/checks/bugprone/forwarding-reference-overload.html Differential Revision: https://phabricator.services.mozilla.com/D304426