libstdc++-v3/testsuite/std/ranges/access/end.cc

   1 // Copyright (C) 2019 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-options "-std=gnu++2a" }
  19 // { dg-do run { target c++2a } }
  20
  21 #include <ranges>
  22 #include <testsuite_hooks.h>
  23 #include <testsuite_iterators.h>
  24
  25 using std::same_as;
  26
  27 void
  28 test01()
  29 {
  30   int a[2] = {};
  31
  32   static_assert(same_as<decltype(std::ranges::end(a)), decltype(a + 2)>);
  33   static_assert(noexcept(std::ranges::end(a)));
  34   VERIFY( std::ranges::end(a) == (a + 2) );
  35 }
  36
  37 void
  38 test02()
  39 {
  40   using __gnu_test::test_range;
  41   using __gnu_test::random_access_iterator_wrapper;
  42   using __gnu_test::input_iterator_wrapper;
  43   using __gnu_test::output_iterator_wrapper;
  44
  45   int a[] = { 0, 1 };
  46
  47   test_range<int, random_access_iterator_wrapper> r(a);
  48   static_assert(same_as<decltype(std::ranges::end(r)), decltype(r.end())>);
  49   VERIFY( std::ranges::end(r) == r.end() );
  50
  51   test_range<int, input_iterator_wrapper> i(a);
  52   static_assert(same_as<decltype(std::ranges::end(i)), decltype(i.end())>);
  53   VERIFY( std::ranges::end(i) == i.end() );
  54
  55   test_range<int, output_iterator_wrapper> o(a);
  56   static_assert(same_as<decltype(std::ranges::end(o)), decltype(o.end())>);
  57   VERIFY( std::ranges::end(o) == std::ranges::next(o.begin(), 2) );
  58 }
  59
  60 struct R
  61 {
  62   int a[4] = { 0, 1, 2, 3 };
  63
  64   const int* begin() const;
  65   friend int* begin(R&&) noexcept;
  66   friend const int* begin(const R&&) noexcept;
  67
  68   // Should be ignored because it doesn't return a sentinel for int*
  69   const long* end() const;
  70
  71   friend int* end(R& r) { return r.a + 0; }
  72   friend int* end(R&& r) { return r.a + 1; }
  73   friend const int* end(const R& r) noexcept { return r.a + 2; }
  74   friend const int* end(const R&& r) noexcept { return r.a + 3; }
  75 };
  76
  77 struct RV // view on an R
  78 {
  79   R& r;
  80
  81   const int* begin() const;
  82
  83   friend int* end(RV& v) noexcept { return end(v.r); }
  84   friend const int* end(const RV& v) { return end(std::as_const(v.r)); }
  85 };
  86
  87 // Allow ranges::begin to work with RV&&
  88 template<> constexpr bool std::ranges::enable_safe_range<RV> = true;
  89
  90 void
  91 test03()
  92 {
  93   R r;
  94   const R& c = r;
  95
  96   static_assert(same_as<decltype(std::ranges::end(r)), decltype(end(r))>);
  97   static_assert(!noexcept(std::ranges::end(r)));
  98   VERIFY( std::ranges::end(r) == end(r) );
  99
 100   static_assert(same_as<decltype(std::ranges::end(c)), decltype(end(c))>);
 101   static_assert(noexcept(std::ranges::end(c)));
 102   VERIFY( std::ranges::end(c) == end(c) );
 103
 104   RV v{r};
 105   static_assert(same_as<decltype(std::ranges::end(std::move(v))),
 106                 decltype(end(r))>);
 107   static_assert(noexcept(std::ranges::end(std::move(v))));
 108   VERIFY( std::ranges::end(std::move(v)) == end(r) );
 109
 110   const RV cv{r};
 111   static_assert(same_as<decltype(std::ranges::end(std::move(cv))),
 112                 decltype(end(c))>);
 113   static_assert(!noexcept(std::ranges::end(std::move(cv))));
 114   VERIFY( std::ranges::end(std::move(cv)) == end(c) );
 115 }
 116
 117 struct RR
 118 {
 119   short s = 0;
 120   long l = 0;
 121   int a[4] = { 0, 1, 2, 3 };
 122
 123   const void* begin() const; // return type not an iterator
 124
 125   friend const short* begin(RR&) noexcept;
 126   short* end() noexcept { return &s; }
 127
 128   friend const long* begin(const RR&) noexcept;
 129   const long* end() const { return &l; }
 130
 131   friend const int* begin(RR&&) noexcept;
 132   friend int* end(RR&) { throw 1; } // not valid for rvalues
 133   friend int* end(RR&& r) { return r.a + 1; }
 134
 135   friend const int* begin(const RR&&) noexcept;
 136   friend const int* end(const RR&) { throw 1; } // not valid for rvalues
 137   friend const int* end(const RR&& r) noexcept { return r.a + 3; }
 138 };
 139
 140 // N.B. this is a lie, end on an RR rvalue will return a dangling pointer.
 141 template<> constexpr bool std::ranges::enable_safe_range<RR> = true;
 142
 143 void
 144 test04()
 145 {
 146   RR r;
 147   const RR& c = r;
 148   VERIFY( std::ranges::end(r) == &r.s );
 149   static_assert(noexcept(std::ranges::end(r)));
 150
 151   VERIFY( std::ranges::end(std::move(r)) == &r.s );
 152   static_assert(noexcept(std::ranges::end(std::move(r))));
 153
 154   VERIFY( std::ranges::end(c) == &r.l );
 155   static_assert(!noexcept(std::ranges::end(c)));
 156
 157   VERIFY( std::ranges::end(std::move(c)) == &r.l );
 158   static_assert(!noexcept(std::ranges::end(std::move(c))));
 159 }
 160
 161 int
 162 main()
 163 {
 164   test01();
 165   test02();
 166   test03();
 167   test04();
 168 }