Tested aarch64-linux. I plan to push this to fix an error when using trunk with Clang.
-- >8 -- We were relying on P1814R0 (CTAD for alias templates) which isn't supported by Clang. We can just not use CTAD and provide an explicit template argument list for _Utf32_view. Ideally we'd define a deduction guide for _Grapheme_cluster_view that uses views::all_t to properly convert non-views to views, but all_t is defined in <ranges> and we don't want to include all of that in <bits/unicode.h>. So just make it require a view for now, which can be cheaply copied. Although it's not needed yet, it would also be more correct to specialize enable_borrowed_range for the views in <bits/unicode.h>. libstdc++-v3/ChangeLog: * include/bits/unicode.h (_Grapheme_cluster_view): Require view. Do not use CTAD for _Utf32_view. (__format_width, __truncate): Do not use CTAD. (enable_borrowed_range<_Utf_view<T, R>>): Define specialization. (enable_borrowed_range<_Grapheme_cluster_view<R>>): Likewise. --- libstdc++-v3/include/bits/unicode.h | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/libstdc++-v3/include/bits/unicode.h b/libstdc++-v3/include/bits/unicode.h index f1b2b359bdf..d35c83d0090 100644 --- a/libstdc++-v3/include/bits/unicode.h +++ b/libstdc++-v3/include/bits/unicode.h @@ -714,15 +714,15 @@ inline namespace __v15_1_0 }; // Split a range into extended grapheme clusters. - template<ranges::forward_range _View> + template<ranges::forward_range _View> requires ranges::view<_View> class _Grapheme_cluster_view : public ranges::view_interface<_Grapheme_cluster_view<_View>> { public: constexpr - _Grapheme_cluster_view(const _View& __v) - : _M_begin(_Utf32_view(__v).begin()) + _Grapheme_cluster_view(_View __v) + : _M_begin(_Utf32_view<_View>(std::move(__v)).begin()) { } constexpr auto begin() const { return _M_begin; } @@ -946,7 +946,7 @@ inline namespace __v15_1_0 { if (__s.empty()) [[unlikely]] return 0; - _Grapheme_cluster_view __gc(__s); + _Grapheme_cluster_view<basic_string_view<_CharT>> __gc(__s); auto __it = __gc.begin(); const auto __end = __gc.end(); size_t __n = __it.width(); @@ -964,7 +964,7 @@ inline namespace __v15_1_0 if (__s.empty()) [[unlikely]] return 0; - _Grapheme_cluster_view __gc(__s); + _Grapheme_cluster_view<basic_string_view<_CharT>> __gc(__s); auto __it = __gc.begin(); const auto __end = __gc.end(); size_t __n = __it.width(); @@ -1058,6 +1058,19 @@ inline namespace __v15_1_0 } // namespace __unicode +namespace ranges +{ + template<typename _To, typename _Range> + inline constexpr bool + enable_borrowed_range<std::__unicode::_Utf_view<_To, _Range>> + = enable_borrowed_range<_Range>; + + template<typename _Range> + inline constexpr bool + enable_borrowed_range<std::__unicode::_Grapheme_cluster_view<_Range>> + = enable_borrowed_range<_Range>; +} // namespace ranges + _GLIBCXX_END_NAMESPACE_VERSION } // namespace std #endif // C++20 -- 2.43.0