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 // <array> 11 12 // template <class T, size_t N> void swap(array<T,N>& x, array<T,N>& y); 13 14 #include <array> 15 #include <cassert> 16 17 #include "test_macros.h" 18 // std::array is explicitly allowed to be initialized with A a = { init-list };. 19 // Disable the missing braces warning for this reason. 20 #include "disable_missing_braces_warning.h" 21 22 struct NonSwappable { 23 NonSwappable() {} 24 private: 25 NonSwappable(NonSwappable const&); 26 NonSwappable& operator=(NonSwappable const&); 27 }; 28 29 template <class Tp> 30 decltype(swap(std::declval<Tp>(), std::declval<Tp>())) 31 can_swap_imp(int); 32 33 template <class Tp> 34 std::false_type can_swap_imp(...); 35 36 template <class Tp> 37 struct can_swap : std::is_same<decltype(can_swap_imp<Tp>(0)), void> {}; 38 39 int main() 40 { 41 { 42 typedef double T; 43 typedef std::array<T, 3> C; 44 C c1 = {1, 2, 3.5}; 45 C c2 = {4, 5, 6.5}; 46 swap(c1, c2); 47 assert(c1.size() == 3); 48 assert(c1[0] == 4); 49 assert(c1[1] == 5); 50 assert(c1[2] == 6.5); 51 assert(c2.size() == 3); 52 assert(c2[0] == 1); 53 assert(c2[1] == 2); 54 assert(c2[2] == 3.5); 55 } 56 { 57 typedef double T; 58 typedef std::array<T, 0> C; 59 C c1 = {}; 60 C c2 = {}; 61 swap(c1, c2); 62 assert(c1.size() == 0); 63 assert(c2.size() == 0); 64 } 65 { 66 typedef NonSwappable T; 67 typedef std::array<T, 0> C0; 68 static_assert(can_swap<C0&>::value, ""); 69 C0 l = {}; 70 C0 r = {}; 71 swap(l, r); 72 #if TEST_STD_VER >= 11 73 static_assert(noexcept(swap(l, r)), ""); 74 #endif 75 } 76 #if TEST_STD_VER >= 11 77 { 78 // NonSwappable is still considered swappable in C++03 because there 79 // is no access control SFINAE. 80 typedef NonSwappable T; 81 typedef std::array<T, 42> C1; 82 static_assert(!can_swap<C1&>::value, ""); 83 } 84 #endif 85 } 86
