Implement P0457R2: 'String Prefix and Suffix Checking' for c++2a

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@319687 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/strings/basic.string/string.ends_with/ends_with.char.pass.cpp

@@ -0,0 +1,34 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+
+// <string>
+
+//   bool ends_with(charT x) const noexcept;
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+
+int main()
+{
+    {
+    typedef std::string S;
+    S  s1 {};
+    S  s2 { "abcde", 5 };
+
+    ASSERT_NOEXCEPT(s1.ends_with('e'));
+
+    assert (!s1.ends_with('e'));
+    assert (!s1.ends_with('x'));
+    assert ( s2.ends_with('e'));
+    assert (!s2.ends_with('x'));
+    }
+}