test: Suppress exception-required tests.

test/strings/basic.string/string.access/at.xfail.pass.cpp

@@ -0,0 +1,44 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// const_reference at(size_type pos) const;
+//       reference at(size_type pos);
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+template <class S>
+void
+test(S s, typename S::size_type pos)
+{
+    try
+    {
+        const S& cs = s;
+        assert(s.at(pos) == s[pos]);
+        assert(cs.at(pos) == cs[pos]);
+        assert(pos < cs.size());
+    }
+    catch (std::out_of_range&)
+    {
+        assert(pos >= s.size());
+    }
+}
+
+int main()
+{
+    typedef std::string S;
+    test(S(), 0);
+    test(S("123"), 0);
+    test(S("123"), 1);
+    test(S("123"), 2);
+    test(S("123"), 3);
+}