https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96710
--- Comment #6 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:4faa42ac0dee2c26ed68f0df002837e7e1c95687 commit r16-2190-g4faa42ac0dee2c26ed68f0df002837e7e1c95687 Author: Jonathan Wakely <jwak...@redhat.com> Date: Fri May 16 13:33:23 2025 +0100 libstdc++: Treat __int128 as a real integral type [PR96710] Since LWG 3828 (included in C++23) implementations are allowed to have extended integer types that are wider than intmax_t. This means we no longer have to make is_integral_v<__int128> false for strict -std=c++23 mode, removing the confusing inconsistency with -std=gnu++23 (where is_integral_v<__int128> is true). This change makes __int128 a true integral type for all modes, treating LWG 3828 as a DR for previous standards. Most of the change just involves removing special cases where we wanted to treat __int128 and unsigned __int128 as integral types even when is_integral_v was false. There are still some preprocessor conditionals needed, because on some targets the compiler defines the macro __GLIBCXX_TYPE_INT_N_0 as __int128 in non-strict modes. Because we define explicit specializations of templates such as is_integral for all the INT_N types, we already have a specialization of is_integral<__int128> in non-strict modes, and so to avoid a redefinition we only must only define is_integral<__int128> for strict modes. libstdc++-v3/ChangeLog: PR libstdc++/96710 * include/bits/cpp_type_traits.h (__is_integer): Define explicit specializations for __int128. (__memcpyable_integer): Remove explicit specializations for __int128. * include/bits/iterator_concepts.h (incrementable_traits): Likewise. (__is_signed_int128, __is_unsigned_int128, __is_int128): Remove. (__is_integer_like, __is_signed_integer_like): Remove check for __int128. * include/bits/max_size_type.h: Remove all uses of __is_int128 in constraints. * include/bits/ranges_base.h (__to_unsigned_like): Remove overloads for __int128. (ranges::ssize): Remove special case for __int128. * include/bits/stl_algobase.h (__size_to_integer): Define __int128 overloads for strict modes. * include/ext/numeric_traits.h (__is_integer_nonstrict): Remove explicit specializations for __int128. * include/std/charconv (to_chars): Define overloads for __int128. * include/std/format (__format::make_unsigned_t): Remove. (__format::to_chars): Remove. * include/std/limits (numeric_limits): Define explicit specializations for __int128. * include/std/type_traits (__is_integral_helper): Likewise. (__make_unsigned, __make_signed): Likewise. Reviewed-by: Patrick Palka <ppa...@redhat.com>
