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

include/array

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]);
 }