Added static_assert to std::get<N>(std::array) calls to catch "out of bounds" calls

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@170435 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/array b/include/array
index 029bfd0..f4a3020 100644
--- a/include/array
+++ b/include/array
@@ -310,6 +310,7 @@
 _Tp&
 get(array<_Tp, _Size>& __a) _NOEXCEPT
 {
+    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array)");
     return __a[_Ip];
 }
 
@@ -318,6 +319,7 @@
 const _Tp&
 get(const array<_Tp, _Size>& __a) _NOEXCEPT
 {
+    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array)");
     return __a[_Ip];
 }
 
@@ -328,6 +330,7 @@
 _Tp&&
 get(array<_Tp, _Size>&& __a) _NOEXCEPT
 {
+    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array &&)");
     return _VSTD::move(__a[_Ip]);
 }
 
diff --git a/test/containers/sequences/array/array.tuple/get.fail.cpp b/test/containers/sequences/array/array.tuple/get.fail.cpp
new file mode 100644
index 0000000..26aa5c7
--- /dev/null
+++ b/test/containers/sequences/array/array.tuple/get.fail.cpp
@@ -0,0 +1,25 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// <array>
+
+// template <size_t I, class T, size_t N> T& get(array<T, N>& a);
+
+#include <array>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef double T;
+        typedef std::array<T, 3> C;
+        C c = {1, 2, 3.5};
+        std::get<3>(c) = 5.5;	// Can't get element 3!
+    }
+}