text: //===----------------------------------------------------------------------===//
  //
  //                     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_view>
  
  // constexpr int compare(const charT* s) const;
  
  #include <experimental/string_view>
  #include <cassert>
  
  #include "test_macros.h"
  #include "constexpr_char_traits.hpp"
  
  int sign ( int x ) { return x > 0 ? 1 : ( x < 0 ? -1 : 0 ); }
  
  template<typename CharT>
  void test1 ( std::experimental::basic_string_view<CharT> sv1, const CharT *s, int expected ) {
      assert ( sign( sv1.compare(s)) == sign(expected));
  }
  
  template<typename CharT>
  void
  test( const CharT *s1, const CharT *s2, int expected)
  {
      typedef std::experimental::basic_string_view<CharT> string_view_t;
      string_view_t sv1 ( s1 );
      test1 ( sv1, s2, expected );
  }
  
  int main()
  {
      {
      test("", "", 0);
      test("", "abcde", -5);
      test("", "abcdefghij", -10);
      test("", "abcdefghijklmnopqrst", -20);
      test("abcde", "", 5);
      test("abcde", "abcde", 0);
      test("abcde", "abcdefghij", -5);
      test("abcde", "abcdefghijklmnopqrst", -15);
      test("abcdefghij", "", 10);
      test("abcdefghij", "abcde", 5);
      test("abcdefghij", "abcdefghij", 0);
      test("abcdefghij", "abcdefghijklmnopqrst", -10);
      test("abcdefghijklmnopqrst", "", 20);
      test("abcdefghijklmnopqrst", "abcde", 15);
      test("abcdefghijklmnopqrst", "abcdefghij", 10);
      test("abcdefghijklmnopqrst", "abcdefghijklmnopqrst", 0);
      }
  
      {
      test(L"", L"", 0);
      test(L"", L"abcde", -5);
      test(L"", L"abcdefghij", -10);
      test(L"", L"abcdefghijklmnopqrst", -20);
      test(L"abcde", L"", 5);
      test(L"abcde", L"abcde", 0);
      test(L"abcde", L"abcdefghij", -5);
      test(L"abcde", L"abcdefghijklmnopqrst", -15);
      test(L"abcdefghij", L"", 10);
      test(L"abcdefghij", L"abcde", 5);
      test(L"abcdefghij", L"abcdefghij", 0);
      test(L"abcdefghij", L"abcdefghijklmnopqrst", -10);
      test(L"abcdefghijklmnopqrst", L"", 20);
      test(L"abcdefghijklmnopqrst", L"abcde", 15);
      test(L"abcdefghijklmnopqrst", L"abcdefghij", 10);
      test(L"abcdefghijklmnopqrst", L"abcdefghijklmnopqrst", 0);
      }
  
  #if TEST_STD_VER >= 11
      {
      test(U"", U"", 0);
      test(U"", U"abcde", -5);
      test(U"", U"abcdefghij", -10);
      test(U"", U"abcdefghijklmnopqrst", -20);
      test(U"abcde", U"", 5);
      test(U"abcde", U"abcde", 0);
      test(U"abcde", U"abcdefghij", -5);
      test(U"abcde", U"abcdefghijklmnopqrst", -15);
      test(U"abcdefghij", U"", 10);
      test(U"abcdefghij", U"abcde", 5);
      test(U"abcdefghij", U"abcdefghij", 0);
      test(U"abcdefghij", U"abcdefghijklmnopqrst", -10);
      test(U"abcdefghijklmnopqrst", U"", 20);
      test(U"abcdefghijklmnopqrst", U"abcde", 15);
      test(U"abcdefghijklmnopqrst", U"abcdefghij", 10);
      test(U"abcdefghijklmnopqrst", U"abcdefghijklmnopqrst", 0);
      }
  
      {
      test(u"", u"", 0);
      test(u"", u"abcde", -5);
      test(u"", u"abcdefghij", -10);
      test(u"", u"abcdefghijklmnopqrst", -20);
      test(u"abcde", u"", 5);
      test(u"abcde", u"abcde", 0);
      test(u"abcde", u"abcdefghij", -5);
      test(u"abcde", u"abcdefghijklmnopqrst", -15);
      test(u"abcdefghij", u"", 10);
      test(u"abcdefghij", u"abcde", 5);
      test(u"abcdefghij", u"abcdefghij", 0);
      test(u"abcdefghij", u"abcdefghijklmnopqrst", -10);
      test(u"abcdefghijklmnopqrst", u"", 20);
      test(u"abcdefghijklmnopqrst", u"abcde", 15);
      test(u"abcdefghijklmnopqrst", u"abcdefghij", 10);
      test(u"abcdefghijklmnopqrst", u"abcdefghijklmnopqrst", 0);
      }
  #endif
  
  #if TEST_STD_VER > 11
      {
      typedef std::experimental::basic_string_view<char, constexpr_char_traits<char>> SV;
      constexpr SV  sv1;
      constexpr SV  sv2 { "abcde", 5 };
      static_assert ( sv1.compare("") == 0, "" );
      static_assert ( sv1.compare("abcde") == -1, "" );
      static_assert ( sv2.compare("") == 1, "" );
      static_assert ( sv2.compare("abcde") == 0, "" );
      }
  #endif
  }
  