libcxx/test/std/strings/string.view/string.view.iterators/begin.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 begin() const;
  12
  13 #include <string_view>
  14 #include <cassert>
  15
  16 #include "test_macros.h"
  17
  18 template <class S>
  19 void
  20 test(S s)
  21 {
  22     const S& cs = s;
  23     typename S::iterator b = s.begin();
  24     typename S::const_iterator cb1 = cs.begin();
  25     typename S::const_iterator cb2 = s.cbegin();
  26     if (!s.empty())
  27     {
  28         assert(   *b ==  s[0]);
  29         assert(  &*b == &s[0]);
  30         assert( *cb1 ==  s[0]);
  31         assert(&*cb1 == &s[0]);
  32         assert( *cb2 ==  s[0]);
  33         assert(&*cb2 == &s[0]);
  34
  35     }
  36     assert(  b == cb1);
  37     assert(  b == cb2);
  38     assert(cb1 == cb2);
  39 }
  40
  41
  42 int main(int, char**)
  43 {
  44     typedef std::string_view    string_view;
  45 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
  46     typedef std::u8string_view  u8string_view;
  47 #endif
  48     typedef std::u16string_view u16string_view;
  49     typedef std::u32string_view u32string_view;
  50     typedef std::wstring_view   wstring_view;
  51
  52     test(string_view   ());
  53     test(u16string_view());
  54     test(u32string_view());
  55     test(wstring_view  ());
  56     test(string_view   ( "123"));
  57     test(wstring_view  (L"123"));
  58 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
  59     test(u8string_view{u8"123"});
  60 #endif
  61 #if TEST_STD_VER >= 11
  62     test(u16string_view{u"123"});
  63     test(u32string_view{U"123"});
  64 #endif
  65
  66 #if TEST_STD_VER > 11
  67     {
  68     constexpr string_view       sv { "123", 3 };
  69 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
  70     constexpr u8string_view u8sv  {u8"123", 3 };
  71 #endif
  72     constexpr u16string_view u16sv {u"123", 3 };
  73     constexpr u32string_view u32sv {U"123", 3 };
  74     constexpr wstring_view     wsv {L"123", 3 };
  75
  76     static_assert (    *sv.begin() ==    sv[0], "" );
  77 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
  78     static_assert (  *u8sv.begin() ==  u8sv[0], "" );
  79 #endif
  80     static_assert ( *u16sv.begin() == u16sv[0], "" );
  81     static_assert ( *u32sv.begin() == u32sv[0], "" );
  82     static_assert (   *wsv.begin() ==   wsv[0], "" );
  83
  84     static_assert (    *sv.cbegin() ==    sv[0], "" );
  85 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
  86     static_assert (  *u8sv.cbegin() ==  u8sv[0], "" );
  87 #endif
  88     static_assert ( *u16sv.cbegin() == u16sv[0], "" );
  89     static_assert ( *u32sv.cbegin() == u32sv[0], "" );
  90     static_assert (   *wsv.cbegin() ==   wsv[0], "" );
  91     }
  92 #endif
  93
  94   return 0;
  95 }