1 files changed, 55 insertions, 0 deletions
diff --git a/test/std/utilities/template.bitset/bitset.members/left_shift_eq.pass.cpp b/test/std/utilities/template.bitset/bitset.members/left_shift_eq.pass.cpp
new file mode 100644
index 0000000000000..bed3e28ece818
--- /dev/null
+++ b/test/std/utilities/template.bitset/bitset.members/left_shift_eq.pass.cpp
@@ -0,0 +1,55 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// test bitset<N>& operator<<=(size_t pos);
+
+#include <bitset>
+#include <cstdlib>
+#include <cassert>
+
+#pragma clang diagnostic ignored "-Wtautological-compare"
+
+template <std::size_t N>
+std::bitset<N>
+make_bitset()
+{
+    std::bitset<N> v;
+    for (std::size_t i = 0; i < N; ++i)
+        v[i] = static_cast<bool>(std::rand() & 1);
+    return v;
+}
+
+template <std::size_t N>
+void test_left_shift()
+{
+    for (std::size_t s = 0; s <= N+1; ++s)
+    {
+        std::bitset<N> v1 = make_bitset<N>();
+        std::bitset<N> v2 = v1;
+        v1 <<= s;
+        for (std::size_t i = 0; i < N; ++i)
+            if (i < s)
+                assert(v1[i] == 0);
+            else
+                assert(v1[i] == v2[i-s]);
+    }
+}
+
+int main()
+{
+    test_left_shift<0>();
+    test_left_shift<1>();
+    test_left_shift<31>();
+    test_left_shift<32>();
+    test_left_shift<33>();
+    test_left_shift<63>();
+    test_left_shift<64>();
+    test_left_shift<65>();
+    test_left_shift<1000>();
+}