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> 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> 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> 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> 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> 57 void test_const_array( const T (&array)[Sz] ) 58 { 59 ASSERT_NOEXCEPT(std::empty(array)); 60 assert (!std::empty(array)); 61 } 62 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