https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122981
--- Comment #3 from Matthias Kretz (Vir) <mkretz at gcc dot gnu.org> --- Christophe, your comment "why would arm-linux-gnueabihf support this type" is exactly where I'm stuck - but my question goes the other way: Why would arm-none-eabi not support the implicit conversion. It's that way on aarch64 and arm-linux-gnueabi(hf). Why does none-eabi have a different API for NEON intrinsics? I'm struggling to see this as a libstdc++ issue. It seems like a frontend issue to me. (Also: How do I build arm-none-eabi on Linux x86_64?)
