libcxx/test/std/strings/string.view/string.view.access/at.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 // <string_view>
  10
  11 // constexpr const _CharT& at(size_type _pos) const;
  12
  13 #include <string_view>
  14 #include <stdexcept>
  15 #include <cassert>
  16
  17 #include "test_macros.h"
  18
  19 template <typename CharT>
  20 void test(const CharT* s, std::size_t len) {
  21   std::basic_string_view<CharT> sv(s, len);
  22   assert(sv.length() == len);
  23   for (std::size_t i = 0; i < len; ++i) {
  24     assert(sv.at(i) == s[i]);
  25     assert(&sv.at(i) == s + i);
  26   }
  27
  28 #ifndef TEST_HAS_NO_EXCEPTIONS
  29   try {
  30     (void)sv.at(len);
  31   } catch (const std::out_of_range&) {
  32     return;
  33   }
  34   assert(false);
  35 #endif
  36 }
  37
  38 int main(int, char**) {
  39   test("ABCDE", 5);
  40   test("a", 1);
  41
  42 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  43   test(L"ABCDE", 5);
  44   test(L"a", 1);
  45 #endif
  46
  47 #if TEST_STD_VER >= 11
  48   test(u"ABCDE", 5);
  49   test(u"a", 1);
  50
  51   test(U"ABCDE", 5);
  52   test(U"a", 1);
  53 #endif
  54
  55 #if TEST_STD_VER >= 11
  56   {
  57     constexpr std::basic_string_view<char> sv("ABC", 2);
  58     static_assert(sv.length() == 2, "");
  59     static_assert(sv.at(0) == 'A', "");
  60     static_assert(sv.at(1) == 'B', "");
  61   }
  62 #endif
  63
  64   return 0;
  65 }