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 // type_traits 13 14 // is_swappable 15 16 #include <type_traits> 17 #include <vector> 18 #include "test_macros.h" 19 20 namespace MyNS { 21 22 // Make the test types non-copyable so that generic std::swap is not valid. 23 struct A { 24 A(A const&) = delete; 25 A& operator=(A const&) = delete; 26 }; 27 28 struct B { 29 B(B const&) = delete; 30 B& operator=(B const&) = delete; 31 }; 32 33 void swap(A&, A&) noexcept {} 34 void swap(B&, B&) {} 35 36 struct M { 37 M(M const&) = delete; 38 M& operator=(M const&) = delete; 39 }; 40 41 void swap(M&&, M&&) noexcept {} 42 43 struct ThrowingMove { 44 ThrowingMove(ThrowingMove&&) {} 45 ThrowingMove& operator=(ThrowingMove&&) { return *this; } 46 }; 47 48 } // namespace MyNS 49 50 int main() 51 { 52 using namespace MyNS; 53 { 54 // Test that is_swappable applies an lvalue reference to the type. 55 static_assert(std::is_nothrow_swappable<int>::value, ""); 56 static_assert(std::is_nothrow_swappable<int&>::value, ""); 57 static_assert(!std::is_nothrow_swappable<M>::value, ""); 58 static_assert(!std::is_nothrow_swappable<M&&>::value, ""); 59 } 60 { 61 // Test that it correctly deduces the noexcept of swap. 62 static_assert(std::is_nothrow_swappable<A>::value, ""); 63 static_assert(!std::is_nothrow_swappable<B>::value 64 && std::is_swappable<B>::value, ""); 65 static_assert(!std::is_nothrow_swappable<ThrowingMove>::value 66 && std::is_swappable<ThrowingMove>::value, ""); 67 } 68 { 69 // Test that it doesn't drop the qualifiers 70 static_assert(!std::is_nothrow_swappable<const A>::value, ""); 71 } 72 { 73 // test non-referenceable types 74 static_assert(!std::is_nothrow_swappable<void>::value, ""); 75 static_assert(!std::is_nothrow_swappable<int() const>::value, ""); 76 static_assert(!std::is_nothrow_swappable<int(int, ...) const &>::value, ""); 77 } 78 { 79 // test for presence of is_nothrow_swappable_v 80 static_assert(std::is_nothrow_swappable_v<int>, ""); 81 static_assert(!std::is_nothrow_swappable_v<void>, ""); 82 } 83 } 84
