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 <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   {
  24     SV sv1(s);
  25     SV sv2;
  26
  27     assert(sv1.size() == len);
  28     assert(sv1.data() == s);
  29     assert(sv2.size() == 0);
  30
  31     sv1.swap(sv2);
  32     assert(sv1.size() == 0);
  33     assert(sv2.size() == len);
  34     assert(sv2.data() == s);
  35   }
  36 }
  37
  38 #if TEST_STD_VER > 11
  39 constexpr std::size_t test_ce(size_t n, size_t k) {
  40   typedef std::basic_string_view<char> SV;
  41   SV sv1{"ABCDEFGHIJKL", n};
  42   SV sv2{sv1.data(), k};
  43   sv1.swap(sv2);
  44   return sv1.size();
  45 }
  46 #endif
  47
  48 int main(int, char**) {
  49   test("ABCDE", 5);
  50   test("a", 1);
  51   test("", 0);
  52
  53 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  54   test(L"ABCDE", 5);
  55   test(L"a", 1);
  56   test(L"", 0);
  57 #endif
  58
  59 #if TEST_STD_VER >= 11
  60   test(u"ABCDE", 5);
  61   test(u"a", 1);
  62   test(u"", 0);
  63
  64   test(U"ABCDE", 5);
  65   test(U"a", 1);
  66   test(U"", 0);
  67 #endif
  68
  69 #if TEST_STD_VER > 11
  70   {
  71     static_assert(test_ce(2, 3) == 3, "");
  72     static_assert(test_ce(5, 3) == 3, "");
  73     static_assert(test_ce(0, 1) == 1, "");
  74   }
  75 #endif
  76
  77   return 0;
  78 }