https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116755
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Issue 2: std println treats duration<int8_t>(54) as char '6' d2 "6s" I think issue 2 is not an bug and it happens with libc++ too. issue 1 does seem like a bug though.