1 //===----------------------------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 // <utility> 11 12 // class make_integer_sequence 13 14 #include <tuple> 15 #include <utility> 16 #include <type_traits> 17 #include <cassert> 18 19 #if _LIBCPP_STD_VER > 11 20 21 template <typename AtContainer, typename T, T... I> 22 auto extract ( const AtContainer &t, const std::integer_sequence<T, I...> idx ) 23 -> decltype ( std::make_tuple ( std::get<I>(t)... )) 24 { return std::make_tuple ( std::get<I>(t)... ); } 25 26 #endif // _LIBCPP_STD_VER > 11 27 28 int main() 29 { 30 #if _LIBCPP_STD_VER > 11 31 32 // Make a couple of sequences 33 using int3 = std::make_integer_sequence<int, 3>; // generates int: 0,1,2 34 using size7 = std::make_integer_sequence<size_t, 7>; // generates size_t: 0,1,2,3,4,5,6 35 using size4 = std::make_index_sequence<4>; // generates size_t: 0,1,2,3 36 using size2 = std::index_sequence_for<int, size_t>; // generates size_t: 0,1 37 using intmix = std::integer_sequence<int, 9, 8, 7, 2>; // generates int: 9,8,7,2 38 using sizemix = std::index_sequence<1, 1, 2, 3, 5>; // generates size_t: 1,1,2,3,5 39 40 // Make sure they're what we expect 41 static_assert ( std::is_same<int3::value_type, int>::value, "int3 type wrong" ); 42 static_assert ( int3::size () == 3, "int3 size wrong" ); 43 44 static_assert ( std::is_same<size7::value_type, size_t>::value, "size7 type wrong" ); 45 static_assert ( size7::size () == 7, "size7 size wrong" ); 46 47 static_assert ( std::is_same<size4::value_type, size_t>::value, "size4 type wrong" ); 48 static_assert ( size4::size () == 4, "size4 size wrong" ); 49 50 static_assert ( std::is_same<size2::value_type, size_t>::value, "size2 type wrong" ); 51 static_assert ( size2::size () == 2, "size2 size wrong" ); 52 53 static_assert ( std::is_same<intmix::value_type, int>::value, "intmix type wrong" ); 54 static_assert ( intmix::size () == 4, "intmix size wrong" ); 55 56 static_assert ( std::is_same<sizemix::value_type, size_t>::value, "sizemix type wrong" ); 57 static_assert ( sizemix::size () == 5, "sizemix size wrong" ); 58 59 auto tup = std::make_tuple ( 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 ); 60 61 // Use them 62 auto t3 = extract ( tup, int3() ); 63 static_assert ( std::tuple_size<decltype(t3)>::value == int3::size (), "t3 size wrong"); 64 assert ( t3 == std::make_tuple ( 10, 11, 12 )); 65 66 auto t7 = extract ( tup, size7 ()); 67 static_assert ( std::tuple_size<decltype(t7)>::value == size7::size (), "t7 size wrong"); 68 assert ( t7 == std::make_tuple ( 10, 11, 12, 13, 14, 15, 16 )); 69 70 auto t4 = extract ( tup, size4 ()); 71 static_assert ( std::tuple_size<decltype(t4)>::value == size4::size (), "t4 size wrong"); 72 assert ( t4 == std::make_tuple ( 10, 11, 12, 13 )); 73 74 auto t2 = extract ( tup, size2 ()); 75 static_assert ( std::tuple_size<decltype(t2)>::value == size2::size (), "t2 size wrong"); 76 assert ( t2 == std::make_tuple ( 10, 11 )); 77 78 auto tintmix = extract ( tup, intmix ()); 79 static_assert ( std::tuple_size<decltype(tintmix)>::value == intmix::size (), "tintmix size wrong"); 80 assert ( tintmix == std::make_tuple ( 19, 18, 17, 12 )); 81 82 auto tsizemix = extract ( tup, sizemix ()); 83 static_assert ( std::tuple_size<decltype(tsizemix)>::value == sizemix::size (), "tsizemix size wrong"); 84 assert ( tsizemix == std::make_tuple ( 11, 11, 12, 13, 15 )); 85 #endif // _LIBCPP_STD_VER > 11 86 } 87
