libcxx/test/std/strings/string.view/string.view.iterators/rend.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_iterator rend() const;
  12
  13 #include <string_view>
  14 #include <cassert>
  15 #include <cstddef>
  16
  17 #include "test_macros.h"
  18
  19 template <class S>
  20 void
  21 test(S s)
  22 {
  23     const S& cs = s;
  24     typename S::reverse_iterator e = s.rend();
  25     typename S::const_reverse_iterator ce1 = cs.rend();
  26     typename S::const_reverse_iterator ce2 = s.crend();
  27
  28     if (s.empty())
  29     {
  30         assert(  e ==  s.rbegin());
  31         assert(ce1 == cs.rbegin());
  32         assert(ce2 ==  s.rbegin());
  33     }
  34     else
  35     {
  36         assert(  e !=  s.rbegin());
  37         assert(ce1 != cs.rbegin());
  38         assert(ce2 !=  s.rbegin());
  39     }
  40
  41     assert(static_cast<std::size_t>(  e -  s.rbegin()) == s.size());
  42     assert(static_cast<std::size_t>(ce1 - cs.rbegin()) == cs.size());
  43     assert(static_cast<std::size_t>(ce2 - s.crbegin()) == s.size());
  44
  45     assert(  e == ce1);
  46     assert(  e == ce2);
  47     assert(ce1 == ce2);
  48 }
  49
  50
  51 int main(int, char**)
  52 {
  53     typedef std::string_view    string_view;
  54 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
  55     typedef std::u8string_view u8string_view;
  56 #endif
  57     typedef std::u16string_view u16string_view;
  58     typedef std::u32string_view u32string_view;
  59     typedef std::wstring_view   wstring_view;
  60
  61     test(string_view   ());
  62     test(u16string_view());
  63     test(u32string_view());
  64     test(wstring_view  ());
  65     test(string_view   ( "123"));
  66     test(wstring_view  (L"123"));
  67 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
  68     test(u8string_view{u8"123"});
  69 #endif
  70 #if TEST_STD_VER >= 11
  71     test(u16string_view{u"123"});
  72     test(u32string_view{U"123"});
  73 #endif
  74
  75 #if TEST_STD_VER > 14
  76     {
  77     constexpr string_view       sv { "123", 3 };
  78 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
  79     constexpr u8string_view u8sv {u8"123", 3 };
  80 #endif
  81     constexpr u16string_view u16sv {u"123", 3 };
  82     constexpr u32string_view u32sv {U"123", 3 };
  83     constexpr wstring_view     wsv {L"123", 3 };
  84
  85     static_assert (    *--sv.rend() ==    sv[0], "" );
  86 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
  87     static_assert (  *--u8sv.rend() ==  u8sv[0], "" );
  88 #endif
  89     static_assert ( *--u16sv.rend() == u16sv[0], "" );
  90     static_assert ( *--u32sv.rend() == u32sv[0], "" );
  91     static_assert (   *--wsv.rend() ==   wsv[0], "" );
  92
  93     static_assert (    *--sv.crend() ==    sv[0], "" );
  94 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
  95     static_assert (  *--u8sv.crend() ==  u8sv[0], "" );
  96 #endif
  97     static_assert ( *--u16sv.crend() == u16sv[0], "" );
  98     static_assert ( *--u32sv.crend() == u32sv[0], "" );
  99     static_assert (   *--wsv.crend() ==   wsv[0], "" );
 100     }
 101 #endif
 102
 103   return 0;
 104 }