https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91356
--- Comment #11 from Niels Möller <nisse at lysator dot liu.se> --- Here's a bit more docs on using std::unique_ptr [[clang::trivial_abi]] with clang and its C++ library. https://libcxx.llvm.org//DesignDocs/UniquePtrTrivialAbi.html As for "No, it needs co-operation between G++ and all other compilers using the same ABI", I would think that if gcc and clang could agree, others would start moving.