1 // Copyright (C) 2020 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 <algorithm>
22 #include <testsuite_hooks.h>
23 #include <testsuite_iterators.h>
24 
25 using __gnu_test::test_container;
26 using __gnu_test::test_range;
27 using __gnu_test::input_iterator_wrapper;
28 using __gnu_test::output_iterator_wrapper;
29 using __gnu_test::forward_iterator_wrapper;
30 
31 namespace ranges = std::ranges;
32 
33 void
test01()34 test01()
35 {
36   const int c[6] = { 1, 2, 3, 4, 5, 6 };
37 
38     {
39       int x[6] = { 7, 8, 9, 4, 5, 6 };
40       int a = 1;
41       VERIFY( ranges::generate_n(x, 3, [&] { return a++; }) == x+3 );
42       VERIFY( ranges::equal(x, c) );
43     }
44 
45     {
46       int x[6] = { 7, 8, 9, 4, 5, 6 };
47       int a = 1;
48       test_container<int, forward_iterator_wrapper> cx(x);
49       VERIFY( *ranges::generate_n(cx.begin(), 3, [&] { return a++; })
50 	       == 4 );
51       VERIFY( ranges::equal(cx, c) );
52     }
53 
54     {
55       int x[6] = { 7, 8, 9, 4, 5, 6 };
56       int a = 1;
57       test_range<int, output_iterator_wrapper> rx(x);
58       ranges::generate_n(ranges::begin(rx), 3, [&] { return a++; });
59       VERIFY( ranges::equal(x, c) );
60     }
61 }
62 
63 constexpr bool
test02()64 test02()
65 {
66   bool ok = true;
67   int c[6] = { 1, 2, 3, 4, 5, 6 };
68   int x[6];
69   int a = 1;
70   ranges::generate_n(x, 6, [&] { return a++; });
71   ok &= ranges::equal(x, c);
72   ranges::generate_n(c, 0, [] { return -1; });
73   ok &= ranges::equal(x, c);
74   ranges::generate_n(c, -2, [] { return -1; });
75   ok &= ranges::equal(x, c);
76   return ok;
77 }
78 
79 int
main()80 main()
81 {
82   test01();
83   static_assert(test02());
84 }
85