AK: Implement reverse iterator for Vector class

cubiclove · Mar 9, 2022 · b0e74a3 · b0e74a3
1 parent 74650b4
commit b0e74a3
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diff --git a/AK/Vector.h b/AK/Vector.h
@@ -13,6 +13,7 @@
 #include <AK/Forward.h>
 #include <AK/Iterator.h>
 #include <AK/Optional.h>
+#include <AK/ReverseIterator.h>
 #include <AK/Span.h>
 #include <AK/StdLibExtras.h>
 #include <AK/Traits.h>
@@ -693,12 +694,15 @@ requires(!IsRvalueReference<T>) class Vector {
 
  using ConstIterator = SimpleIterator<Vector const, VisibleType const>;
  using Iterator = SimpleIterator<Vector, VisibleType>;
+ using ReverseIterator = SimpleReverseIterator<Vector, VisibleType>;
 
  ConstIterator begin() const { return ConstIterator::begin(*this); }
  Iterator begin() { return Iterator::begin(*this); }
+ ReverseIterator rbegin() { return ReverseIterator::rbegin(*this); }
 
  ConstIterator end() const { return ConstIterator::end(*this); }
  Iterator end() { return Iterator::end(*this); }
+ ReverseIterator rend() { return ReverseIterator::rend(*this); }
 
  template<typename TUnaryPredicate>
  ConstIterator find_if(TUnaryPredicate&& finder) const

diff --git a/Tests/AK/TestVector.cpp b/Tests/AK/TestVector.cpp
@@ -533,3 +533,29 @@ TEST_CASE(reference_deletion_should_not_affect_object)
  }
  EXPECT_EQ(times_deleted, 1u);
 }
+
+TEST_CASE(rbegin)
+{
+ Vector<int> v { 1, 2, 3, 4, 5, 6, 7, 8, 0 };
+
+ auto const expected = v.begin() + 4;
+ auto const expected_in_reverse = v.rbegin() + 4;
+ EXPECT_EQ(*expected, *expected_in_reverse);
+}
+
+TEST_CASE(rend)
+{
+ Vector<int> v { 1, 2, 3, 4, 5, 6, 7, 8, 0 };
+
+ const auto expected = v.end() - 5;
+ const auto expected_in_reverse = v.rend() - 5;
+ EXPECT_EQ(*expected, *expected_in_reverse);
+}
+
+TEST_CASE(reverse_loop)
+{
+ Vector<int> v { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
+ int index = 9;
+ for (auto rev = v.rbegin(); rev != v.rend(); ++rev)
+ EXPECT_EQ(*rev, index--);
+}