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// UNSUPPORTED: c++03, c++11
10// <utility>
11
12// class make_integer_sequence
13
14#include <tuple>
15#include <utility>
16#include <type_traits>
17#include <cassert>
18
19#include "test_macros.h"
20
21template <typename AtContainer, typename T, T... I>
22auto extract ( const AtContainer &t, const std::integer_sequence<T, I...> )
23-> decltype ( std::make_tuple ( std::get<I>(t)... ))
24{ return std::make_tuple ( std::get<I>(t)... ); }
25
26int main(int, char**)
27{
28// Make a couple of sequences
29 using int3 = std::make_integer_sequence<int, 3>; // generates int: 0,1,2
30 using size7 = std::make_integer_sequence<std::size_t, 7>; // generates size_t: 0,1,2,3,4,5,6
31 using size4 = std::make_index_sequence<4>; // generates size_t: 0,1,2,3
32 using size2 = std::index_sequence_for<int, std::size_t>; // generates size_t: 0,1
33 using intmix = std::integer_sequence<int, 9, 8, 7, 2>; // generates int: 9,8,7,2
34 using sizemix = std::index_sequence<1, 1, 2, 3, 5>; // generates size_t: 1,1,2,3,5
35
36// Make sure they're what we expect
37 static_assert ( std::is_same<int3::value_type, int>::value, "int3 type wrong" );
38 static_assert ( int3::size () == 3, "int3 size wrong" );
39
40 static_assert ( std::is_same<size7::value_type, std::size_t>::value, "size7 type wrong" );
41 static_assert ( size7::size () == 7, "size7 size wrong" );
42
43 static_assert ( std::is_same<size4::value_type, std::size_t>::value, "size4 type wrong" );
44 static_assert ( size4::size () == 4, "size4 size wrong" );
45
46 static_assert ( std::is_same<size2::value_type, std::size_t>::value, "size2 type wrong" );
47 static_assert ( size2::size () == 2, "size2 size wrong" );
48
49 static_assert ( std::is_same<intmix::value_type, int>::value, "intmix type wrong" );
50 static_assert ( intmix::size () == 4, "intmix size wrong" );
51
52 static_assert ( std::is_same<sizemix::value_type, std::size_t>::value, "sizemix type wrong" );
53 static_assert ( sizemix::size () == 5, "sizemix size wrong" );
54
55 auto tup = std::make_tuple ( args: 10, args: 11, args: 12, args: 13, args: 14, args: 15, args: 16, args: 17, args: 18, args: 19, args: 20 );
56
57// Use them
58 auto t3 = extract ( tup, int3() );
59 static_assert ( std::tuple_size<decltype(t3)>::value == int3::size (), "t3 size wrong");
60 assert ( t3 == std::make_tuple ( 10, 11, 12 ));
61
62 auto t7 = extract ( tup, size7 ());
63 static_assert ( std::tuple_size<decltype(t7)>::value == size7::size (), "t7 size wrong");
64 assert ( t7 == std::make_tuple ( 10, 11, 12, 13, 14, 15, 16 ));
65
66 auto t4 = extract ( tup, size4 ());
67 static_assert ( std::tuple_size<decltype(t4)>::value == size4::size (), "t4 size wrong");
68 assert ( t4 == std::make_tuple ( 10, 11, 12, 13 ));
69
70 auto t2 = extract ( tup, size2 ());
71 static_assert ( std::tuple_size<decltype(t2)>::value == size2::size (), "t2 size wrong");
72 assert ( t2 == std::make_tuple ( 10, 11 ));
73
74 auto tintmix = extract ( tup, intmix ());
75 static_assert ( std::tuple_size<decltype(tintmix)>::value == intmix::size (), "tintmix size wrong");
76 assert ( tintmix == std::make_tuple ( 19, 18, 17, 12 ));
77
78 auto tsizemix = extract ( tup, sizemix ());
79 static_assert ( std::tuple_size<decltype(tsizemix)>::value == sizemix::size (), "tsizemix size wrong");
80 assert ( tsizemix == std::make_tuple ( 11, 11, 12, 13, 15 ));
81
82 return 0;
83}
84

source code of libcxx/test/std/utilities/intseq/intseq.general/integer_seq.pass.cpp