1// Copyright Louis Dionne 2013-2022
2// Distributed under the Boost Software License, Version 1.0.
3// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
4
5#include <boost/hana/assert.hpp>
6#include <boost/hana/first.hpp>
7#include <boost/hana/pair.hpp>
8#include <boost/hana/second.hpp>
9namespace hana = boost::hana;
10
11
12struct MoveOnly {
13 int data_;
14 MoveOnly(MoveOnly const&) = delete;
15 MoveOnly& operator=(MoveOnly const&) = delete;
16 MoveOnly(int data) : data_(data) { }
17 MoveOnly(MoveOnly&& x) : data_(x.data_) { x.data_ = 0; }
18
19 MoveOnly& operator=(MoveOnly&& x)
20 { data_ = x.data_; x.data_ = 0; return *this; }
21
22 bool operator==(const MoveOnly& x) const { return data_ == x.data_; }
23};
24
25class FromInt {
26 int data_;
27public:
28 constexpr FromInt(int data) : data_(data) { }
29 constexpr bool operator==(const FromInt& x) const { return data_ == x.data_; }
30};
31
32int main() {
33 //////////////////////////////////////////////////////////////////////////
34 // Check for the pair(T&&, U&&) constructor
35 //////////////////////////////////////////////////////////////////////////
36 {
37 hana::pair<MoveOnly, short*> p(MoveOnly{3}, nullptr);
38 BOOST_HANA_RUNTIME_CHECK(hana::first(p) == MoveOnly{3});
39 BOOST_HANA_RUNTIME_CHECK(hana::second(p) == nullptr);
40 }
41
42 //////////////////////////////////////////////////////////////////////////
43 // Check for the pair(First const&, Second const&) constructor
44 //////////////////////////////////////////////////////////////////////////
45 {
46 hana::pair<float, short*> p1(3.5f, 0);
47 BOOST_HANA_RUNTIME_CHECK(hana::first(p1) == 3.5f);
48 BOOST_HANA_RUNTIME_CHECK(hana::second(p1) == nullptr);
49
50 // brace init
51 hana::pair<float, short*> p2 = {3.5f, 0};
52 BOOST_HANA_RUNTIME_CHECK(hana::first(p2) == 3.5f);
53 BOOST_HANA_RUNTIME_CHECK(hana::second(p2) == nullptr);
54 }
55 {
56 hana::pair<FromInt, int> p1(1, 2);
57 BOOST_HANA_RUNTIME_CHECK(hana::first(p1) == FromInt(1));
58 BOOST_HANA_RUNTIME_CHECK(hana::second(p1) == 2);
59
60 // brace init
61 hana::pair<FromInt, int> p2 = {1, 2};
62 BOOST_HANA_RUNTIME_CHECK(hana::first(p2) == FromInt(1));
63 BOOST_HANA_RUNTIME_CHECK(hana::second(p2) == 2);
64 }
65
66 // Make sure the above works constexpr too
67 {
68 constexpr hana::pair<float, short*> p1(3.5f, 0);
69 static_assert(hana::first(p1) == 3.5f, "");
70 static_assert(hana::second(p1) == nullptr, "");
71
72 // brace init
73 constexpr hana::pair<float, short*> p2 = {3.5f, 0};
74 static_assert(hana::first(p2) == 3.5f, "");
75 static_assert(hana::second(p2) == nullptr, "");
76 }
77 {
78 constexpr hana::pair<FromInt, int> p1(1, 2);
79 static_assert(hana::first(p1) == FromInt(1), "");
80 static_assert(hana::second(p1) == 2, "");
81
82 // brace init
83 constexpr hana::pair<FromInt, int> p2 = {1, 2};
84 static_assert(hana::first(p2) == FromInt(1), "");
85 static_assert(hana::second(p2) == 2, "");
86 }
87}
88

source code of boost/libs/hana/test/pair/cnstr.memberwise.cpp