Tested on x86_64-pc-linux-gnu, does this look OK for trunk?
libstdc++-v3/ChangeLog:
* include/bits/ranges_algo.h (__contains_fn, contains): Define.
(__contains_subrange_fn, contains_subrange): Define.
* testsuite/25_algorithms/contains/1.cc: New test.
* testsuite/25_algorithms/contains_subrange/1.cc: New test.
---
libstdc++-v3/include/bits/ranges_algo.h | 54 +++++++++++++++++++
.../testsuite/25_algorithms/contains/1.cc | 33 ++++++++++++
.../25_algorithms/contains_subrange/1.cc | 35 ++++++++++++
3 files changed, 122 insertions(+)
create mode 100644 libstdc++-v3/testsuite/25_algorithms/contains/1.cc
create mode 100644 libstdc++-v3/testsuite/25_algorithms/contains_subrange/1.cc
diff --git a/libstdc++-v3/include/bits/ranges_algo.h
b/libstdc++-v3/include/bits/ranges_algo.h
index de71bd07a2f..da0ca981dc3 100644
--- a/libstdc++-v3/include/bits/ranges_algo.h
+++ b/libstdc++-v3/include/bits/ranges_algo.h
@@ -3464,6 +3464,60 @@ namespace ranges
inline constexpr __prev_permutation_fn prev_permutation{};
+#if __cplusplus > 202002L
+ struct __contains_fn
+ {
+ template<input_iterator _Iter, sentinel_for<_Iter> _Sent,
+ typename _Tp, typename _Proj = identity>
+ requires indirect_binary_predicate<ranges::equal_to,
+ projected<_Iter, _Proj>, const _Tp*>
+ constexpr bool
+ operator()(_Iter __first, _Sent __last, const _Tp& __value, _Proj __proj
= {}) const
+ { return ranges::find(std::move(__first), __last, __value, __proj) !=
__last; }
+
+ template<input_range _Range, typename _Tp, typename _Proj = identity>
+ requires indirect_binary_predicate<ranges::equal_to,
+ projected<iterator_t<_Range>, _Proj>,
const _Tp*>
+ constexpr bool
+ operator()(_Range&& __r, const _Tp& __value, _Proj __proj = {}) const
+ { return (*this)(ranges::begin(__r), ranges::end(__r), __value,
std::move(__proj)); }
+ };
+
+ inline constexpr __contains_fn contains{};
+
+ struct __contains_subrange_fn
+ {
+ template<forward_iterator _Iter1, sentinel_for<_Iter1> _Sent1,
+ forward_iterator _Iter2, sentinel_for<_Iter2> _Sent2,
+ typename _Pred = ranges::equal_to,
+ typename Proj1 = identity, typename Proj2 = identity>
+ requires indirectly_comparable<_Iter1, _Iter2, _Pred, Proj1, Proj2>
+ constexpr bool
+ operator()(_Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2
__last2,
+ _Pred __pred = {}, Proj1 __proj1 = {}, Proj2 __proj2 = {})
const
+ {
+ return __first2 == __last2
+ || !ranges::search(__first1, __last1, __first2, __last2,
+ std::move(__pred), std::move(__proj1),
std::move(__proj2)).empty();
+ }
+
+ template<forward_range _Range1, forward_range _Range2,
+ typename _Pred = ranges::equal_to,
+ typename _Proj1 = identity, typename _Proj2 = identity>
+ requires indirectly_comparable<iterator_t<_Range1>, iterator_t<_Range2>,
+ _Pred, _Proj1, _Proj2>
+ constexpr bool
+ operator()(_Range1&& __r1, _Range2&& __r2, _Pred __pred = {},
+ _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) const
+ {
+ return (*this)(ranges::begin(__r1), ranges::end(__r1),
+ ranges::begin(__r2), ranges::end(__r2),
+ std::move(__pred), std::move(__proj1),
std::move(__proj2));
+ }
+ };
+
+ inline constexpr __contains_subrange_fn contains_subrange{};
+#endif // C++23
} // namespace ranges
#define __cpp_lib_shift 201806L
diff --git a/libstdc++-v3/testsuite/25_algorithms/contains/1.cc
b/libstdc++-v3/testsuite/25_algorithms/contains/1.cc
new file mode 100644
index 00000000000..146ab593b70
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/contains/1.cc
@@ -0,0 +1,33 @@
+// { dg-options "-std=gnu++23" }
+// { dg-do run { target c++23 } }
+
+#include <algorithm>
+#include <testsuite_hooks.h>
+#include <testsuite_iterators.h>
+
+namespace ranges = std::ranges;
+
+void
+test01()
+{
+ int x[] = {1,2,3};
+ using to_input = __gnu_test::test_input_range<int>;
+ VERIFY( ranges::contains(to_input(x), 1) );
+ VERIFY( ranges::contains(to_input(x), 2) );
+ VERIFY( ranges::contains(to_input(x), 3) );
+ VERIFY( !ranges::contains(to_input(x), 4) );
+ VERIFY( !ranges::contains(x, x+2, 3) );
+ auto neg = [](int n) { return -n; };
+ VERIFY( ranges::contains(to_input(x), -1, neg) );
+ VERIFY( ranges::contains(to_input(x), -2, neg) );
+ VERIFY( ranges::contains(to_input(x), -3, neg) );
+ VERIFY( !ranges::contains(to_input(x), -4, neg) );
+
+ VERIFY( !ranges::contains(x, x+2, -3, neg) );
+}
+
+int
+main()
+{
+ test01();
+}
diff --git a/libstdc++-v3/testsuite/25_algorithms/contains_subrange/1.cc
b/libstdc++-v3/testsuite/25_algorithms/contains_subrange/1.cc
new file mode 100644
index 00000000000..62b92795f94
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/contains_subrange/1.cc
@@ -0,0 +1,35 @@
+// { dg-options "-std=gnu++23" }
+// { dg-do run { target c++23 } }
+
+#include <algorithm>
+#include <testsuite_hooks.h>
+#include <testsuite_iterators.h>
+
+namespace ranges = std::ranges;
+
+void
+test01()
+{
+ int x[] = {1,2,3,4,5};
+ int y[] = {2,3,4};
+ int z[] = {4,5,6};
+ __gnu_test::test_forward_range<int> rx(x);
+ __gnu_test::test_forward_range<int> ry(y);
+ __gnu_test::test_forward_range<int> rz(z);
+ VERIFY( ranges::contains_subrange(rx, ry) );
+ VERIFY( !ranges::contains_subrange(rx, rz) );
+ VERIFY( ranges::contains_subrange(rx, ry, ranges::less{}) );
+ VERIFY( ranges::contains_subrange(rx, rz, ranges::less{}) );
+ auto plus3 = [](int n) { return n+3; };
+ VERIFY( !ranges::contains_subrange(rx, ry, ranges::equal_to{}, plus3) );
+ VERIFY( ranges::contains_subrange(rx, rz, ranges::equal_to{}, plus3) );
+
+ VERIFY( ranges::contains_subrange(x, x+2, y, y+1) );
+ VERIFY( !ranges::contains_subrange(x, x+2, y, y+2) );
+}
+
+int
+main()
+{
+ test01();
+}
--
2.38.1.420.g319605f8f0
