1 files changed, 87 insertions, 0 deletions
diff --git a/libcxx/test/std/containers/sequences/deque/deque.special/copy_backward.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.special/copy_backward.pass.cpp
new file mode 100644
index 00000000000..b484a865c57
--- /dev/null
+++ b/libcxx/test/std/containers/sequences/deque/deque.special/copy_backward.pass.cpp
@@ -0,0 +1,87 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <deque>
+
+// Optimization for deque::iterators
+
+// template <class InputIterator, class OutputIterator>
+//   OutputIterator
+//   copy_backward(InputIterator first, InputIterator last, OutputIterator result);
+
+#include <deque>
+#include <cassert>
+
+#include "test_iterators.h"
+#include "min_allocator.h"
+
+template <class C>
+C
+make(int size, int start = 0 )
+{
+    const int b = 4096 / sizeof(int);
+    int init = 0;
+    if (start > 0)
+    {
+        init = (start+1) / b + ((start+1) % b != 0);
+        init *= b;
+        --init;
+    }
+    C c(init, 0);
+    for (int i = 0; i < init-start; ++i)
+        c.pop_back();
+    for (int i = 0; i < size; ++i)
+        c.push_back(i);
+    for (int i = 0; i < start; ++i)
+        c.pop_front();
+    return c;
+};
+
+template <class C>
+void testN(int start, int N)
+{
+    typedef typename C::iterator I;
+    typedef typename C::const_iterator CI;
+    typedef random_access_iterator<I> RAI;
+    typedef random_access_iterator<CI> RACI;
+    C c1 = make<C>(N, start);
+    C c2 = make<C>(N);
+    assert(std::copy_backward(c1.cbegin(), c1.cend(), c2.end()) == c2.begin());
+    assert(c1 == c2);
+    assert(std::copy_backward(c2.cbegin(), c2.cend(), c1.end()) == c1.begin());
+    assert(c1 == c2);
+    assert(std::copy_backward(c1.cbegin(), c1.cend(), RAI(c2.end())) == RAI(c2.begin()));
+    assert(c1 == c2);
+    assert(std::copy_backward(c2.cbegin(), c2.cend(), RAI(c1.end())) == RAI(c1.begin()));
+    assert(c1 == c2);
+    assert(std::copy_backward(RACI(c1.cbegin()), RACI(c1.cend()), c2.end()) == c2.begin());
+    assert(c1 == c2);
+    assert(std::copy_backward(RACI(c2.cbegin()), RACI(c2.cend()), c1.end()) == c1.begin());
+    assert(c1 == c2);
+}
+
+int main()
+{
+    {
+    int rng[] = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
+    const int N = sizeof(rng)/sizeof(rng[0]);
+    for (int i = 0; i < N; ++i)
+        for (int j = 0; j < N; ++j)
+            testN<std::deque<int> >(rng[i], rng[j]);
+    }
+#if __cplusplus >= 201103L
+    {
+    int rng[] = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
+    const int N = sizeof(rng)/sizeof(rng[0]);
+    for (int i = 0; i < N; ++i)
+        for (int j = 0; j < N; ++j)
+            testN<std::deque<int, min_allocator<int>> >(rng[i], rng[j]);
+    }
+#endif
+}