libstdc++-v3/testsuite/24_iterators/counted_iterator/1.cc

   1 // Copyright (C) 2019-2022 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 <iterator>
  22 #include <testsuite_hooks.h>
  23
  24 void
  25 test01()
  26 {
  27   using I = std::counted_iterator<int*>;
  28   static_assert( std::is_default_constructible_v<I> );
  29   static_assert( std::is_copy_constructible_v<I> );
  30   static_assert( std::is_copy_assignable_v<I> );
  31   static_assert( ! std::is_constructible_v<I, int*> );
  32   static_assert( std::is_constructible_v<I, int*, std::ptrdiff_t> );
  33
  34   using J = std::counted_iterator<const int*>;
  35   static_assert( std::is_constructible_v<J, const I&> );
  36   static_assert( std::is_convertible_v<const I&, J> );
  37 }
  38
  39 void
  40 test02()
  41 {
  42   int in[3] = { 1, 2, 3 };
  43   std::counted_iterator<const int*> in_iter(std::begin(in), std::ssize(in));
  44   VERIFY( in_iter.base() == in );
  45   VERIFY( (std::default_sentinel - in_iter) == 3 );
  46   VERIFY( (in_iter - std::default_sentinel) == -3 );
  47
  48   int out[4] = { };
  49   std::counted_iterator<int*> out_iter(std::begin(out), std::ssize(out));
  50   VERIFY( out_iter.base() == out );
  51   VERIFY( (std::default_sentinel - out_iter) == 4 );
  52   VERIFY( (out_iter - std::default_sentinel) == -4 );
  53
  54   while (in_iter != std::default_sentinel && out_iter != std::default_sentinel)
  55     *out_iter++ = *in_iter++;
  56
  57   VERIFY(in_iter == std::default_sentinel);
  58   VERIFY(out_iter != std::default_sentinel);
  59   VERIFY( out[0] == 1 );
  60   VERIFY( out[1] == 2 );
  61   VERIFY( out[2] == 3 );
  62   VERIFY( out[3] == 0 );
  63
  64   auto out2 = out_iter;
  65   out2 += 1;
  66   VERIFY( out2 == std::default_sentinel );
  67   VERIFY( (out2 <=> out_iter) == std::strong_ordering::greater );
  68   out2 -= 3;
  69   VERIFY( (out_iter - out2) == 2 );
  70   VERIFY( (out2 <=> out_iter) == std::strong_ordering::less );
  71 }
  72
  73 void
  74 test03()
  75 {
  76   struct X
  77   {
  78     X(int i) : i(i) { }
  79     X(X&& x) : i(x.i) { x.i = -1; }
  80     X& operator=(X&& x) { i = x.i; x.i = 0; return *this; }
  81     int i;
  82   };
  83
  84   X arr[] = { 1, 2 };
  85   std::counted_iterator<X*> i(arr, 2), j(arr + 1, 1);
  86   std::ranges::iter_swap(i, j);
  87   VERIFY( arr[0].i == 2 );
  88   VERIFY( arr[1].i == 1 );
  89
  90   X x = std::ranges::iter_move(i);
  91   VERIFY( arr[0].i == -1 );
  92   VERIFY( x.i == 2 );
  93 }
  94
  95 int
  96 main()
  97 {
  98   test01();
  99   test02();
 100   test03();
 101 }