1 // Copyright (c) 2019-2021 Antony Polukhin
2 //
3 // Distributed under the Boost Software License, Version 1.0. (See accompanying
4 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
5
6 #include <type_traits>
7
8 #include <boost/pfr/core.hpp>
9
10 template <class T>
11 struct unconstrained_template {
12 unconstrained_template() = default;
13 unconstrained_template(const unconstrained_template&) = default;
14 unconstrained_template(unconstrained_template&&) = default;
15 unconstrained_template& operator=(const unconstrained_template&) = default;
16 unconstrained_template& operator=(unconstrained_template&&) = default;
17
18 template <class U>
unconstrained_templateunconstrained_template19 constexpr unconstrained_template(const U& val)
20 : value_{val}
21 {}
22
23 T value_{};
24 };
25
26 struct int_element {
27 int value_;
28 };
29
30
31 struct aggregate_unconstrained {
32 unconstrained_template<int> a;
33 unconstrained_template<int_element> b;
34 };
35
main()36 int main() {
37 using sanity = decltype(aggregate_unconstrained{
38 boost::pfr::detail::ubiq_lref_constructor{0},
39 boost::pfr::detail::ubiq_lref_constructor{1},
40 });
41 static_assert(
42 std::is_same<
43 sanity, aggregate_unconstrained
44 >::value,
45 "Precise reflection with template constructors sanity check fails"
46 );
47
48 boost::pfr::detail::enable_if_constructible_helper_t<aggregate_unconstrained, 2> foo;
49 (void)foo;
50
51 static_assert(
52 std::is_same<
53 boost::pfr::tuple_element_t<0, aggregate_unconstrained>,
54 unconstrained_template<int>
55 >::value,
56 "Precise reflection with template constructors fails to work"
57 );
58
59 static_assert(
60 std::is_same<
61 boost::pfr::tuple_element_t<1, aggregate_unconstrained>,
62 unconstrained_template<int_element>
63 >::value,
64 "Precise reflection with template constructors fails to work"
65 );
66
67 aggregate_unconstrained aggr{3, 4};
68 return boost::pfr::get<1>(aggr).value_.value_ - 4;
69 }
70