- use = default when relevant - use = delete on public method instead of unimplemented private - use range-based loop This matches the clang-tidy rules: - https://clang.llvm.org/extra/clang-tidy/checks/modernize/use-equals-default.html - https://clang.llvm.org/extra/clang-tidy/checks/modernize/use-equals-delete.html - https://clang.llvm.org/extra/clang-tidy/checks/modernize/loop-convert.html Also had to do minor header tweaking to cope with std::size_t with size_t in the process. That we already use on source files Differential Revision: https://phabricator.services.mozilla.com/D296635