https://gcc.gnu.org/g:700cbeeaf165db9f0350786191541cd3c9b15318
commit r15-11610-g700cbeeaf165db9f0350786191541cd3c9b15318 Author: Jonathan Wakely <[email protected]> Date: Thu Oct 1 21:20:36 2026 +0100 libstdc++: Add enable_borrowed_range<to_input_view<V>> [PR125785] Add the missing partial specialization, and test for it. Also add tests for the as_const_view and as_rvalue_view partial specializations that weren't being tested. libstdc++-v3/ChangeLog: PR libstdc++/125785 * include/std/ranges (enable_borrowed_range<to_input_view<T>>): Define partial specialization. * testsuite/std/ranges/adaptors/to_input/1.cc: Test specialization for to_input_view. * testsuite/std/ranges/adaptors/as_const/1.cc: Test specialization for as_const_view. * testsuite/std/ranges/adaptors/as_rvalue/1.cc: Test specialization for as_rvalue_view. Reviewed-by: Tomasz Kamiński <[email protected]> (cherry picked from commit b8a469b62d85dc9cf8b995e0eece8eaa7f9ba7aa) Diff: --- libstdc++-v3/include/std/ranges | 4 ++++ libstdc++-v3/testsuite/std/ranges/adaptors/as_const/1.cc | 5 +++++ libstdc++-v3/testsuite/std/ranges/adaptors/as_rvalue/1.cc | 6 ++++++ libstdc++-v3/testsuite/std/ranges/adaptors/to_input/1.cc | 6 ++++++ 4 files changed, 21 insertions(+) diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges index 569b681b9fe1..c555b8598128 100644 --- a/libstdc++-v3/include/std/ranges +++ b/libstdc++-v3/include/std/ranges @@ -10460,6 +10460,10 @@ namespace ranges template<typename _Range> to_input_view(_Range&&) -> to_input_view<views::all_t<_Range>>; + template<typename _Vp> + inline constexpr bool enable_borrowed_range<to_input_view<_Vp>> + = enable_borrowed_range<_Vp>; + template<input_range _Vp> requires view<_Vp> template<bool _Const> diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/as_const/1.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/as_const/1.cc index 5ccf47d4d300..135cc2911e93 100644 --- a/libstdc++-v3/testsuite/std/ranges/adaptors/as_const/1.cc +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/as_const/1.cc @@ -81,6 +81,11 @@ test04() VERIFY( ranges::equal(v, x) ); } +using Owning = ranges::single_view<int>; +using Borrowed = std::span<int>; +static_assert( ! ranges::enable_borrowed_range<ranges::as_const_view<Owning>> ); +static_assert( ranges::enable_borrowed_range<ranges::as_const_view<Borrowed>> ); + int main() { diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/as_rvalue/1.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/as_rvalue/1.cc index 487700773705..531560ad84af 100644 --- a/libstdc++-v3/testsuite/std/ranges/adaptors/as_rvalue/1.cc +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/as_rvalue/1.cc @@ -9,6 +9,7 @@ #include <algorithm> #include <memory> +#include <span> #include <testsuite_hooks.h> #include <testsuite_iterators.h> @@ -55,6 +56,11 @@ test02() VERIFY( *y == 42 ); } +using Owning = ranges::single_view<int>; +using Borrowed = std::span<int>; +static_assert( ! ranges::enable_borrowed_range<ranges::as_rvalue_view<Owning>> ); +static_assert( ranges::enable_borrowed_range<ranges::as_rvalue_view<Borrowed>> ); + int main() { diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/to_input/1.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/to_input/1.cc index cde368a2f64d..27167e290a5c 100644 --- a/libstdc++-v3/testsuite/std/ranges/adaptors/to_input/1.cc +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/to_input/1.cc @@ -8,6 +8,7 @@ #include <algorithm> #include <vector> +#include <span> #include <testsuite_hooks.h> #include <testsuite_iterators.h> @@ -51,6 +52,11 @@ test02() decltype(x | views::to_input | views::to_input)> ); } +using Owning = ranges::single_view<int>; +using Borrowed = std::span<int>; +static_assert( ! ranges::enable_borrowed_range<ranges::to_input_view<Owning>> ); +static_assert( ranges::enable_borrowed_range<ranges::to_input_view<Borrowed>> ); + int main() {
