libcxx/test/std/strings/string.view/string.view.modifiers/swap.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 // void swap(basic_string_view& _other) noexcept
  14
  15 #include <cassert>
  16 #include <cstddef>
  17 #include <string_view>
  18
  19 #include "test_macros.h"
  20
  21 template <typename CharT>
  22 void test(const CharT* s, std::size_t len) {
  23   typedef std::basic_string_view<CharT> SV;
  24   {
  25     SV sv1(s);
  26     SV sv2;
  27
  28     assert(sv1.size() == len);
  29     assert(sv1.data() == s);
  30     assert(sv2.size() == 0);
  31
  32     sv1.swap(sv2);
  33     assert(sv1.size() == 0);
  34     assert(sv2.size() == len);
  35     assert(sv2.data() == s);
  36   }
  37 }
  38
  39 #if TEST_STD_VER > 11
  40 constexpr std::size_t test_ce(size_t n, size_t k) {
  41   typedef std::basic_string_view<char> SV;
  42   SV sv1{"ABCDEFGHIJKL", n};
  43   SV sv2{sv1.data(), k};
  44   sv1.swap(sv2);
  45   return sv1.size();
  46 }
  47 #endif
  48
  49 int main(int, char**) {
  50   test("ABCDE", 5);
  51   test("a", 1);
  52   test("", 0);
  53
  54 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  55   test(L"ABCDE", 5);
  56   test(L"a", 1);
  57   test(L"", 0);
  58 #endif
  59
  60 #if TEST_STD_VER >= 11
  61   test(u"ABCDE", 5);
  62   test(u"a", 1);
  63   test(u"", 0);
  64
  65   test(U"ABCDE", 5);
  66   test(U"a", 1);
  67   test(U"", 0);
  68 #endif
  69
  70 #if TEST_STD_VER > 11
  71   {
  72     static_assert(test_ce(2, 3) == 3, "");
  73     static_assert(test_ce(5, 3) == 3, "");
  74     static_assert(test_ce(0, 1) == 1, "");
  75   }
  76 #endif
  77
  78   return 0;
  79 }