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.ptr.pass.cpp

@@ -0,0 +1,63 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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(const CharT *x) const;
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+
+int main()
+{
+    {
+    typedef std::string S;
+    const char *s = "abcde";
+
+    S   s0;
+    S   s1  { s + 4, 1 };
+    S   s2  { s + 3, 2 };
+//  S   s3  { s + 2, 3 };
+//  S   s4  { s + 1, 4 };
+//  S   s5  { s,     5 };
+    S  sNot { "def", 3 };
+    
+    LIBCPP_ASSERT_NOEXCEPT(s0.ends_with(""));
+
+    assert ( s0.ends_with(""));
+    assert (!s0.ends_with("e"));
+
+    assert ( s1.ends_with(""));
+    assert ( s1.ends_with("e"));
+    assert (!s1.ends_with("de"));
+    assert (!s1.ends_with("cde"));
+    assert (!s1.ends_with("bcde"));
+    assert (!s1.ends_with("abcde"));
+    assert (!s1.ends_with("def"));
+
+    assert ( s2.ends_with(""));
+    assert ( s2.ends_with("e"));
+    assert ( s2.ends_with("de"));
+    assert (!s2.ends_with("cde"));
+    assert (!s2.ends_with("bcde"));
+    assert (!s2.ends_with("abcde"));
+    assert (!s2.ends_with("def"));
+
+    assert ( sNot.ends_with(""));
+    assert (!sNot.ends_with("e"));
+    assert (!sNot.ends_with("de"));
+    assert (!sNot.ends_with("cde"));
+    assert (!sNot.ends_with("bcde"));
+    assert (!sNot.ends_with("abcde"));
+    assert ( sNot.ends_with("def"));
+    }
+}