1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 // UNSUPPORTED: c++03, c++11, c++14
10
11 // <iterator>
12 // template <class C> constexpr auto empty(const C& c) -> decltype(c.empty()); // C++17
13 // template <class T, size_t N> constexpr bool empty(const T (&array)[N]) noexcept; // C++17
14 // template <class E> constexpr bool empty(initializer_list<E> il) noexcept; // C++17
15
16 #include <iterator>
17 #include <cassert>
18 #include <vector>
19 #include <array>
20 #include <list>
21 #include <initializer_list>
22
23 #include "test_macros.h"
24
25 #if TEST_STD_VER > 14
26 #include <string_view>
27 #endif
28
29 template<typename C>
test_const_container(const C & c)30 void test_const_container( const C& c )
31 {
32 // Can't say noexcept here because the container might not be
33 assert ( std::empty(c) == c.empty());
34 }
35
36 template<typename T>
test_const_container(const std::initializer_list<T> & c)37 void test_const_container( const std::initializer_list<T>& c )
38 {
39 assert ( std::empty(c) == (c.size() == 0));
40 }
41
42 template<typename C>
test_container(C & c)43 void test_container( C& c )
44 {
45 // Can't say noexcept here because the container might not be
46 assert ( std::empty(c) == c.empty());
47 }
48
49 template<typename T>
test_container(std::initializer_list<T> & c)50 void test_container( std::initializer_list<T>& c )
51 {
52 ASSERT_NOEXCEPT(std::empty(c));
53 assert ( std::empty(c) == (c.size() == 0));
54 }
55
56 template<typename T, size_t Sz>
test_const_array(const T (& array)[Sz])57 void test_const_array( const T (&array)[Sz] )
58 {
59 ASSERT_NOEXCEPT(std::empty(array));
60 assert (!std::empty(array));
61 }
62
main(int,char **)63 int main(int, char**)
64 {
65 std::vector<int> v; v.push_back(1);
66 std::list<int> l; l.push_back(2);
67 std::array<int, 1> a; a[0] = 3;
68 std::initializer_list<int> il = { 4 };
69
70 test_container ( v );
71 test_container ( l );
72 test_container ( a );
73 test_container ( il );
74
75 test_const_container ( v );
76 test_const_container ( l );
77 test_const_container ( a );
78 test_const_container ( il );
79
80 #if TEST_STD_VER > 14
81 std::string_view sv{"ABC"};
82 test_container ( sv );
83 test_const_container ( sv );
84 #endif
85
86 static constexpr int arrA [] { 1, 2, 3 };
87 test_const_array ( arrA );
88
89 return 0;
90 }
91