Packages with the libcxx use flag

sci-physics / root : C++ data analysis framework and interpreter from CERN

  • Build ROOT against sys-libs/libcxx

sys-devel / binutils-apple : Darwin assembler as(1) and static linker ld(1), Xcode Tools 8.2.1

  • Add support for libcxx

sys-devel / clang-runtime : Meta-ebuild for clang runtime libraries

  • Install sys-libs/libcxx for -stdlib=libc++