Created attachment 18393 [details] repro modernize-use-emplace removes constructor calls with initializer-list parameters. After applying fixits, code doesn't compile. Eg. typedef std::vector<unsigned char> Unit; typedef std::vector<Unit> UnitVector; UnitVector InitialCorpus; InitialCorpus.push_back(Unit({'\n'})); // --> InitialCorpus.emplace_back({'\n'}) The bug is present in the 4.0 release.
https://reviews.llvm.org/D32767
Fixed by r302281