1 //===----------------------------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 // UNSUPPORTED: c++98, c++03, c++11, c++14 11 12 // <iterator> 13 // template <class C> constexpr auto empty(const C& c) -> decltype(c.empty()); // C++17 14 // template <class T, size_t N> constexpr bool empty(const T (&array)[N]) noexcept; // C++17 15 // template <class E> constexpr bool empty(initializer_list<E> il) noexcept; // C++17 16 17 #include <iterator> 18 #include <cassert> 19 #include <vector> 20 #include <array> 21 #include <list> 22 #include <initializer_list> 23 24 #include "test_macros.h" 25 26 #if TEST_STD_VER > 14 27 #include <string_view> 28 #endif 29 30 template<typename C> 31 void test_const_container( const C& c ) 32 { 33 // Can't say noexcept here because the container might not be 34 assert ( std::empty(c) == c.empty()); 35 } 36 37 template<typename T> 38 void test_const_container( const std::initializer_list<T>& c ) 39 { 40 assert ( std::empty(c) == (c.size() == 0)); 41 } 42 43 template<typename C> 44 void test_container( C& c ) 45 { 46 // Can't say noexcept here because the container might not be 47 assert ( std::empty(c) == c.empty()); 48 } 49 50 template<typename T> 51 void test_container( std::initializer_list<T>& c ) 52 { 53 ASSERT_NOEXCEPT(std::empty(c)); 54 assert ( std::empty(c) == (c.size() == 0)); 55 } 56 57 template<typename T, size_t Sz> 58 void test_const_array( const T (&array)[Sz] ) 59 { 60 ASSERT_NOEXCEPT(std::empty(array)); 61 assert (!std::empty(array)); 62 } 63 64 int main() 65 { 66 std::vector<int> v; v.push_back(1); 67 std::list<int> l; l.push_back(2); 68 std::array<int, 1> a; a[0] = 3; 69 std::initializer_list<int> il = { 4 }; 70 71 test_container ( v ); 72 test_container ( l ); 73 test_container ( a ); 74 test_container ( il ); 75 76 test_const_container ( v ); 77 test_const_container ( l ); 78 test_const_container ( a ); 79 test_const_container ( il ); 80 81 #if TEST_STD_VER > 14 82 std::string_view sv{"ABC"}; 83 test_container ( sv ); 84 test_const_container ( sv ); 85 #endif 86 87 static constexpr int arrA [] { 1, 2, 3 }; 88 test_const_array ( arrA ); 89 } 90
