[gcc(refs/users/ppalka/heads/libstdcxx-constrained-algos)] Add ranges::unique_copy

Patrick Palka ppalka@gcc.gnu.org
Tue Jan 21 20:17:00 GMT 2020


https://gcc.gnu.org/g:db8c1538676e0a1f42ff13fc6429932487fb4d8e

commit db8c1538676e0a1f42ff13fc6429932487fb4d8e
Author: Patrick Palka <ppalka@gcc.gnu.org>
Date:   Tue Jan 21 15:02:30 2020 -0500

    Add ranges::unique_copy

Diff:
---
 libstdc++-v3/include/bits/ranges_algo.h            |  79 ++++++++++++++
 .../25_algorithms/unique_copy/constrained.cc       | 114 +++++++++++++++++++++
 2 files changed, 193 insertions(+)

diff --git a/libstdc++-v3/include/bits/ranges_algo.h b/libstdc++-v3/include/bits/ranges_algo.h
index 4c9c54b..fb238b1 100644
--- a/libstdc++-v3/include/bits/ranges_algo.h
+++ b/libstdc++-v3/include/bits/ranges_algo.h
@@ -1438,6 +1438,85 @@ namespace ranges
 			      std::move(__comp), std::move(__proj));
       }
 
+    template<class _Iter, class _Out>
+    using unique_copy_result = copy_result<_Iter, _Out>;
+
+    template<input_iterator _Iter, sentinel_for<_Iter> _Sent,
+	     weakly_incrementable _Out, class _Proj = identity,
+	     indirect_equivalence_relation<
+	       projected<_Iter, _Proj>> _Comp = ranges::equal_to>
+      requires indirectly_copyable<_Iter, _Out>
+	&& (forward_iterator<_Iter>
+	    || (input_iterator<_Out>
+		&& same_as<iter_value_t<_Iter>, iter_value_t<_Out>>)
+	    || indirectly_copyable_storable<_Iter, _Out>)
+      constexpr unique_copy_result<_Iter, _Out>
+      unique_copy(_Iter __first, _Sent __last, _Out __result,
+		  _Comp __comp = {}, _Proj __proj = {})
+      {
+	if (__first == __last)
+	  return {__last, __result};
+
+	if constexpr (forward_iterator<_Iter>)
+	  {
+	    auto __next = __first;
+	    *__result = *__next;
+	    while (++__next != __last)
+	      if (!std::__invoke(__comp,
+				 std::__invoke(__proj, *__first),
+				 std::__invoke(__proj, *__next)))
+		{
+		  __first = __next;
+		  *++__result = *__first;
+		}
+	    return {__last, ++__result};
+	  }
+	else if constexpr (input_iterator<_Out>
+			   && same_as<iter_value_t<_Iter>, iter_value_t<_Out>>)
+	  {
+	    *__result = *__first;
+	    while (++__first != __last)
+	      if (!std::__invoke(__comp,
+				 std::__invoke(__proj, *__result),
+				 std::__invoke(__proj, *__first)))
+		  *++__result = *__first;
+	    return {__last, ++__result};
+	  }
+	else // indirectly_copyable_storable<_Iter, _Out>
+	  {
+	    auto __value = *__first;
+	    *__result = __value;
+	    while (++__first != __last)
+	      {
+		if (!std::__invoke(__comp,
+				   std::__invoke(__proj, *__first),
+				   std::__invoke(__proj, __value)))
+		  {
+		    __value = *__first;
+		    *++__result = __value;
+		  }
+	      }
+	    return {__last, ++__result};
+	  }
+      }
+
+    template<input_range _Range,
+	     weakly_incrementable _Out, class _Proj = identity,
+	     indirect_equivalence_relation<
+	       projected<iterator_t<_Range>, _Proj>> _Comp = ranges::equal_to>
+      requires indirectly_copyable<iterator_t<_Range>, _Out>
+	&& (forward_iterator<iterator_t<_Range>>
+	    || (input_iterator<_Out>
+		&& same_as<range_value_t<_Range>, iter_value_t<_Out>>)
+	    || indirectly_copyable_storable<iterator_t<_Range>, _Out>)
+      constexpr unique_copy_result<safe_iterator_t<_Range>, _Out>
+      unique_copy(_Range&& __r, _Out __result,
+		  _Comp __comp = {}, _Proj __proj = {})
+      {
+	return ranges::unique_copy(ranges::begin(__r), ranges::end(__r),
+				   std::move(__result),
+				   std::move(__comp), std::move(__proj));
+      }
 
 } // namespace ranges
 _GLIBCXX_END_NAMESPACE_VERSION
diff --git a/libstdc++-v3/testsuite/25_algorithms/unique_copy/constrained.cc b/libstdc++-v3/testsuite/25_algorithms/unique_copy/constrained.cc
new file mode 100644
index 0000000..2df0c85
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/unique_copy/constrained.cc
@@ -0,0 +1,114 @@
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do run { target c++2a } }
+
+#include <list>
+#include <algorithm>
+#include <testsuite_hooks.h>
+#include <testsuite_iterators.h>
+
+using __gnu_test::test_range;
+using __gnu_test::input_iterator_wrapper;
+using __gnu_test::output_iterator_wrapper;
+using __gnu_test::forward_iterator_wrapper;
+
+namespace ranges = std::ranges;
+
+template<template<typename> typename source_wrapper,
+	 template<typename> typename dest_wrapper>
+void
+test01()
+{
+  int x[6] = {0, 0, 0, 1, 1, 1};
+  int y[2];
+  const int z[2] = {0, 1};
+
+  test_range<int, source_wrapper> rx(x);
+  test_range<int, dest_wrapper> ry(y);
+  auto [in,out] = ranges::unique_copy(rx, ry.begin());
+  VERIFY( in == ranges::end(rx) && out == ranges::end(ry) );
+  VERIFY( ranges::equal(y, z) );
+}
+
+template<template<typename> typename source_wrapper,
+	 template<typename> typename dest_wrapper>
+void
+test02()
+{
+  int x[6] = {0, 0, 0, 1, 1, 1};
+  int y[2] = {0, 0};
+  const int z[2] = {0, 0};
+
+  test_range<int, source_wrapper> rx(x, x);
+  test_range<int, dest_wrapper> ry(y, y);
+  auto [in, out] = ranges::unique_copy(rx.begin(), rx.end(), ry.begin());
+  VERIFY( in.ptr == x && out.ptr == y );
+  VERIFY( ranges::equal(y, z) );
+}
+
+template<template<typename> typename source_wrapper,
+	 template<typename> typename dest_wrapper>
+void
+test03()
+{
+  struct X { int i; };
+  X x[6] = { {1}, {2}, {2}, {4}, {4}, {6} };
+  X y[4] = { {1}, {2}, {4}, {6} };
+  const X z[4] = { {1}, {2}, {4}, {6} };
+
+  test_range<X, source_wrapper> rx(x);
+  test_range<X, dest_wrapper> ry(y);
+  auto [in, out]
+    = ranges::unique_copy(rx, ry.begin(), ranges::equal_to{}, &X::i);
+  VERIFY( in == ranges::end(rx) && out == ranges::end(ry) );
+  VERIFY( ranges::equal(y, z, {}, &X::i, &X::i) );
+}
+
+constexpr bool
+test04()
+{
+  struct X { int i; };
+  X x[7] = { {1}, {2}, {2}, {2}, {4}, {4}, {6} };
+  X y[4] = { {1}, {2}, {4}, {6} };
+  const X z[4] = { {1}, {2}, {4}, {6} };
+
+  auto [in, out]
+    = ranges::unique_copy(x, x+7, y, ranges::equal_to{}, &X::i);
+  return (in == ranges::end(x)
+	  && out == ranges::end(y)
+	  && ranges::equal(y, z, {}, &X::i, &X::i));
+}
+
+int
+main()
+{
+  test01<input_iterator_wrapper, output_iterator_wrapper>();
+  test01<input_iterator_wrapper, forward_iterator_wrapper>();
+  test01<forward_iterator_wrapper, output_iterator_wrapper>();
+
+  test02<input_iterator_wrapper, output_iterator_wrapper>();
+  test02<input_iterator_wrapper, forward_iterator_wrapper>();
+  test02<forward_iterator_wrapper, output_iterator_wrapper>();
+
+  test03<input_iterator_wrapper, output_iterator_wrapper>();
+  test03<input_iterator_wrapper, forward_iterator_wrapper>();
+  test03<forward_iterator_wrapper, output_iterator_wrapper>();
+
+  static_assert(test04());
+}



More information about the Libstdc++-cvs mailing list