1 // -*- C++ -*-
2 //===------------------------------ span ---------------------------------===//
3 //
4 // The LLVM Compiler Infrastructure
5 //
6 // This file is dual licensed under the MIT and the University of Illinois Open
7 // Source Licenses. See LICENSE.TXT for details.
8 //
9 //===---------------------------------------------------------------------===//
10 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
11
12 // <span>
13
14 // template<class Container>
15 // constexpr span(Container& cont);
16 // template<class Container>
17 // constexpr span(const Container& cont);
18 //
19 // Remarks: These constructors shall not participate in overload resolution unless:
20 // — Container is not a specialization of span,
21 // — Container is not a specialization of array,
22 // — is_array_v<Container> is false,
23 // — data(cont) and size(cont) are both well-formed, and
24 // — remove_pointer_t<decltype(data(cont))>(*)[] is convertible to ElementType(*)[].
25 //
26
27
28 #include <span>
29 #include <cassert>
30 #include <list>
31 #include <forward_list>
32 #include <deque>
33
34 #include "test_macros.h"
35
36 // Look ma - I'm a container!
37 template <typename T>
38 struct IsAContainer {
IsAContainerIsAContainer39 constexpr IsAContainer() : v_{} {}
sizeIsAContainer40 constexpr size_t size() const {return 1;}
dataIsAContainer41 constexpr T *data() {return &v_;}
dataIsAContainer42 constexpr const T *data() const {return &v_;}
43
getVIsAContainer44 constexpr const T *getV() const {return &v_;} // for checking
45 T v_;
46 };
47
48 template <typename T>
49 struct NotAContainerNoData {
sizeNotAContainerNoData50 size_t size() const {return 0;}
51 };
52
53 template <typename T>
54 struct NotAContainerNoSize {
dataNotAContainerNoSize55 const T *data() const {return nullptr;}
56 };
57
58 template <typename T>
59 struct NotAContainerPrivate {
60 private:
sizeNotAContainerPrivate61 size_t size() const {return 0;}
dataNotAContainerPrivate62 const T *data() const {return nullptr;}
63 };
64
65
main()66 int main ()
67 {
68
69 // Missing size and/or data
70 {
71 std::span<int> s1{IsAContainer<int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
72 std::span<int, 0> s2{IsAContainer<int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
73 std::span<int> s3{NotAContainerNoData<int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
74 std::span<int, 0> s4{NotAContainerNoData<int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
75 std::span<int> s5{NotAContainerNoSize<int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
76 std::span<int, 0> s6{NotAContainerNoSize<int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
77 std::span<int> s7{NotAContainerPrivate<int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
78 std::span<int, 0> s8{NotAContainerPrivate<int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
79
80 // Again with the standard containers
81 std::span<int> s11{std::deque<int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
82 std::span<int, 0> s12{std::deque<int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
83 std::span<int> s13{std::list<int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
84 std::span<int, 0> s14{std::list<int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
85 std::span<int> s15{std::forward_list<int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
86 std::span<int, 0> s16{std::forward_list<int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
87 }
88
89 // Not the same type
90 {
91 std::span<float> s1{IsAContainer<int>()}; // expected-error {{no matching constructor for initialization of 'std::span<float>'}}
92 std::span<float, 0> s2{IsAContainer<int>()}; // expected-error {{no matching constructor for initialization of 'std::span<float, 0>'}}
93 }
94
95 // CV wrong (dynamically sized)
96 {
97 std::span< int> s1{IsAContainer<const int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
98 std::span< int> s2{IsAContainer< volatile int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
99 std::span< int> s3{IsAContainer<const volatile int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
100 std::span<const int> s4{IsAContainer< volatile int>()}; // expected-error {{no matching constructor for initialization of 'std::span<const int>'}}
101 std::span<const int> s5{IsAContainer<const volatile int>()}; // expected-error {{no matching constructor for initialization of 'std::span<const int>'}}
102 std::span< volatile int> s6{IsAContainer<const int>()}; // expected-error {{no matching constructor for initialization of 'std::span<volatile int>'}}
103 std::span< volatile int> s7{IsAContainer<const volatile int>()}; // expected-error {{no matching constructor for initialization of 'std::span<volatile int>'}}
104 }
105
106 // CV wrong (statically sized)
107 {
108 std::span< int,1> s1{IsAContainer<const int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int, 1>'}}
109 std::span< int,1> s2{IsAContainer< volatile int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int, 1>'}}
110 std::span< int,1> s3{IsAContainer<const volatile int>()}; // expected-error {{no matching constructor for initialization of 'std::span<int, 1>'}}
111 std::span<const int,1> s4{IsAContainer< volatile int>()}; // expected-error {{no matching constructor for initialization of 'std::span<const int, 1>'}}
112 std::span<const int,1> s5{IsAContainer<const volatile int>()}; // expected-error {{no matching constructor for initialization of 'std::span<const int, 1>'}}
113 std::span< volatile int,1> s6{IsAContainer<const int>()}; // expected-error {{no matching constructor for initialization of 'std::span<volatile int, 1>'}}
114 std::span< volatile int,1> s7{IsAContainer<const volatile int>()}; // expected-error {{no matching constructor for initialization of 'std::span<volatile int, 1>'}}
115 }
116
117 }
118