libcxx/test/std/strings/string.view/string.view.access/index.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // UNSUPPORTED: !stdlib=libc++ && (c++03 || c++11 || c++14)
  10
  11 // <string_view>
  12
  13 // constexpr const _CharT& operator[](size_type _pos) const;
  14
  15 #include <string_view>
  16 #include <cassert>
  17
  18 #include "test_macros.h"
  19
  20 template <typename CharT>
  21 void test(const CharT* s, std::size_t len) {
  22   typedef std::basic_string_view<CharT> SV;
  23   SV sv(s, len);
  24   ASSERT_SAME_TYPE(decltype(sv[0]), typename SV::const_reference);
  25   LIBCPP_ASSERT_NOEXCEPT(sv[0]);
  26   assert(sv.length() == len);
  27   for (std::size_t i = 0; i < len; ++i) {
  28     assert(sv[i] == s[i]);
  29     assert(&sv[i] == s + i);
  30   }
  31 }
  32
  33 int main(int, char**) {
  34   test("ABCDE", 5);
  35   test("a", 1);
  36
  37 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  38   test(L"ABCDE", 5);
  39   test(L"a", 1);
  40 #endif
  41
  42 #if TEST_STD_VER >= 11
  43   test(u"ABCDE", 5);
  44   test(u"a", 1);
  45
  46   test(U"ABCDE", 5);
  47   test(U"a", 1);
  48 #endif
  49
  50 #if TEST_STD_VER > 11
  51   {
  52     constexpr std::basic_string_view<char> sv("ABC", 2);
  53     static_assert(sv.length() == 2, "");
  54     static_assert(sv[0] == 'A', "");
  55     static_assert(sv[1] == 'B', "");
  56   }
  57 #endif
  58
  59   return 0;
  60 }