https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105509
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Thiago Macieira from comment #0) > See also https://wg21.link/p1467, notably section 5.10 Literal suffixes That isn't supported yet *at all*. And it's not in the C++ draft yet. The current support in G++ is just "some of the C stuff as an extension", not an attempt to implement P1467. We will need the f16 suffix for C++23 eventually though.