swap_noexcept.pass.cpp (2590B)
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 11 12 // <vector> 13 14 // void swap(vector& c) 15 // noexcept(!allocator_type::propagate_on_container_swap::value || 16 // __is_nothrow_swappable<allocator_type>::value); 17 // 18 // In C++17, the standard says that swap shall have: 19 // noexcept(allocator_traits<Allocator>::propagate_on_container_swap::value || 20 // allocator_traits<Allocator>::is_always_equal::value); 21 22 // This tests a conforming extension 23 24 #include <vector> 25 #include <utility> 26 #include <cassert> 27 28 #include "test_macros.h" 29 #include "MoveOnly.h" 30 #include "test_allocator.h" 31 32 template <class T> 33 struct some_alloc 34 { 35 typedef T value_type; 36 37 some_alloc() {} 38 some_alloc(const some_alloc&); 39 void deallocate(void*, unsigned) {} 40 41 typedef std::true_type propagate_on_container_swap; 42 }; 43 44 template <class T> 45 struct some_alloc2 46 { 47 typedef T value_type; 48 49 some_alloc2() {} 50 some_alloc2(const some_alloc2&); 51 void deallocate(void*, unsigned) {} 52 53 typedef std::false_type propagate_on_container_swap; 54 typedef std::true_type is_always_equal; 55 }; 56 57 int main() 58 { 59 { 60 typedef std::vector<MoveOnly> C; 61 static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), ""); 62 } 63 #if defined(_LIBCPP_VERSION) 64 { 65 typedef std::vector<MoveOnly, test_allocator<MoveOnly>> C; 66 static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), ""); 67 } 68 #endif // _LIBCPP_VERSION 69 { 70 typedef std::vector<MoveOnly, other_allocator<MoveOnly>> C; 71 static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), ""); 72 } 73 { 74 typedef std::vector<MoveOnly, some_alloc<MoveOnly>> C; 75 #if TEST_STD_VER >= 14 76 // In C++14, if POCS is set, swapping the allocator is required not to throw 77 static_assert( noexcept(swap(std::declval<C&>(), std::declval<C&>())), ""); 78 #else 79 static_assert(!noexcept(swap(std::declval<C&>(), std::declval<C&>())), ""); 80 #endif 81 } 82 #if TEST_STD_VER >= 14 83 { 84 typedef std::vector<MoveOnly, some_alloc2<MoveOnly>> C; 85 // if the allocators are always equal, then the swap can be noexcept 86 static_assert( noexcept(swap(std::declval<C&>(), std::declval<C&>())), ""); 87 } 88 #endif 89 }