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 template<typename C> 27 void test_const_container( const C& c ) 28 { 29 // Can't say noexcept here because the container might not be 30 assert ( std::empty(c) == c.empty()); 31 } 32 33 template<typename T> 34 void test_const_container( const std::initializer_list<T>& c ) 35 { 36 assert ( std::empty(c) == (c.size() == 0)); 37 } 38 39 template<typename C> 40 void test_container( C& c ) 41 { 42 // Can't say noexcept here because the container might not be 43 assert ( std::empty(c) == c.empty()); 44 } 45 46 template<typename T> 47 void test_container( std::initializer_list<T>& c ) 48 { 49 ASSERT_NOEXCEPT(std::empty(c)); 50 assert ( std::empty(c) == (c.size() == 0)); 51 } 52 53 template<typename T, size_t Sz> 54 void test_const_array( const T (&array)[Sz] ) 55 { 56 ASSERT_NOEXCEPT(std::empty(array)); 57 assert (!std::empty(array)); 58 } 59 60 int main() 61 { 62 std::vector<int> v; v.push_back(1); 63 std::list<int> l; l.push_back(2); 64 std::array<int, 1> a; a[0] = 3; 65 std::initializer_list<int> il = { 4 }; 66 67 test_container ( v ); 68 test_container ( l ); 69 test_container ( a ); 70 test_container ( il ); 71 72 test_const_container ( v ); 73 test_const_container ( l ); 74 test_const_container ( a ); 75 test_const_container ( il ); 76 77 static constexpr int arrA [] { 1, 2, 3 }; 78 test_const_array ( arrA ); 79 } 80