1// Copyright (c) 2019-2024 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
10template <class T>
11struct 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>
19 constexpr unconstrained_template(const U& val)
20 : value_{val}
21 {}
22
23 T value_{};
24};
25
26struct int_element {
27 int value_;
28};
29
30
31struct aggregate_unconstrained {
32 unconstrained_template<int> a;
33 unconstrained_template<int_element> b;
34};
35
36int main() {
37 using sanity = decltype(aggregate_unconstrained{
38 .a: boost::pfr::detail::ubiq_lref_constructor{.ignore: 0},
39 .b: boost::pfr::detail::ubiq_lref_constructor{.ignore: 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{.a: 3, .b: 4};
68 return boost::pfr::get<1>(val&: aggr).value_.value_ - 4;
69}
70

source code of boost/libs/pfr/test/core/run/template_unconstrained.cpp