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_nothrow_swappable_with 15 16 #include <type_traits> 17 #include <vector> 18 #include "test_macros.h" 19 20 namespace MyNS { 21 22 struct A { 23 A(A const&) = delete; 24 A& operator=(A const&) = delete; 25 }; 26 27 struct B { 28 B(B const&) = delete; 29 B& operator=(B const&) = delete; 30 }; 31 32 struct C {}; 33 struct D {}; 34 35 void swap(A&, A&) {} 36 37 void swap(A&, B&) noexcept {} 38 void swap(B&, A&) noexcept {} 39 40 void swap(A&, C&) noexcept {} 41 void swap(C&, A&) {} 42 43 struct M {}; 44 45 void swap(M&&, M&&) noexcept {} 46 47 } // namespace MyNS 48 49 int main() 50 { 51 using namespace MyNS; 52 { 53 // Test that is_swappable_with doesn't apply an lvalue reference 54 // to the type. Instead it is up to the user. 55 static_assert(!std::is_nothrow_swappable_with<int, int>::value, ""); 56 static_assert(std::is_nothrow_swappable_with<int&, int&>::value, ""); 57 static_assert(std::is_nothrow_swappable_with<M, M>::value, ""); 58 static_assert(std::is_swappable_with<A&, A&>::value && 59 !std::is_nothrow_swappable_with<A&, A&>::value, ""); 60 } 61 { 62 // test that hetrogenius swap is allowed only if both 'swap(A, B)' and 63 // 'swap(B, A)' are valid. 64 static_assert(std::is_nothrow_swappable_with<A&, B&>::value, ""); 65 static_assert(!std::is_nothrow_swappable_with<A&, C&>::value && 66 std::is_swappable_with<A&, C&>::value, ""); 67 static_assert(!std::is_nothrow_swappable_with<D&, C&>::value, ""); 68 } 69 { 70 // test we guard against cv void inputs as required. 71 static_assert(!std::is_nothrow_swappable_with_v<void, int>); 72 static_assert(!std::is_nothrow_swappable_with_v<int, void>); 73 static_assert(!std::is_nothrow_swappable_with_v<const void, const volatile void>); 74 75 } 76 { 77 // test for presense of is_nothrow_swappable_with_v 78 static_assert(std::is_nothrow_swappable_with_v<int&, int&>); 79 static_assert(!std::is_nothrow_swappable_with_v<int&&, int&&>); 80 } 81 } 82
