| //===----------------------------------------------------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is dual licensed under the MIT and the University of Illinois Open |
| // Source Licenses. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // type_traits |
| |
| // is_empty |
| |
| // T is a non-union class type with: |
| // no non-static data members, |
| // no unnamed bit-fields of non-zero length, |
| // no virtual member functions, |
| // no virtual base classes, |
| // and no base class B for which is_empty_v<B> is false. |
| |
| |
| #include <type_traits> |
| #include "test_macros.h" |
| |
| template <class T> |
| void test_is_empty() |
| { |
| static_assert( std::is_empty<T>::value, ""); |
| static_assert( std::is_empty<const T>::value, ""); |
| static_assert( std::is_empty<volatile T>::value, ""); |
| static_assert( std::is_empty<const volatile T>::value, ""); |
| #if TEST_STD_VER > 14 |
| static_assert( std::is_empty_v<T>, ""); |
| static_assert( std::is_empty_v<const T>, ""); |
| static_assert( std::is_empty_v<volatile T>, ""); |
| static_assert( std::is_empty_v<const volatile T>, ""); |
| #endif |
| } |
| |
| template <class T> |
| void test_is_not_empty() |
| { |
| static_assert(!std::is_empty<T>::value, ""); |
| static_assert(!std::is_empty<const T>::value, ""); |
| static_assert(!std::is_empty<volatile T>::value, ""); |
| static_assert(!std::is_empty<const volatile T>::value, ""); |
| #if TEST_STD_VER > 14 |
| static_assert(!std::is_empty_v<T>, ""); |
| static_assert(!std::is_empty_v<const T>, ""); |
| static_assert(!std::is_empty_v<volatile T>, ""); |
| static_assert(!std::is_empty_v<const volatile T>, ""); |
| #endif |
| } |
| |
| class Empty {}; |
| struct NotEmpty { int foo; }; |
| |
| class VirtualFn |
| { |
| virtual ~VirtualFn(); |
| }; |
| |
| union Union {}; |
| |
| struct EmptyBase : public Empty {}; |
| struct VirtualBase : virtual Empty {}; |
| struct NotEmptyBase : public NotEmpty {}; |
| |
| struct StaticMember { static int foo; }; |
| struct NonStaticMember { int foo; }; |
| |
| struct bit_zero |
| { |
| int : 0; |
| }; |
| |
| struct bit_one |
| { |
| int : 1; |
| }; |
| |
| int main() |
| { |
| test_is_not_empty<void>(); |
| test_is_not_empty<int&>(); |
| test_is_not_empty<int>(); |
| test_is_not_empty<double>(); |
| test_is_not_empty<int*>(); |
| test_is_not_empty<const int*>(); |
| test_is_not_empty<char[3]>(); |
| test_is_not_empty<char[]>(); |
| test_is_not_empty<Union>(); |
| test_is_not_empty<NotEmpty>(); |
| test_is_not_empty<VirtualFn>(); |
| test_is_not_empty<VirtualBase>(); |
| test_is_not_empty<NotEmptyBase>(); |
| test_is_not_empty<NonStaticMember>(); |
| test_is_empty<bit_one>(); |
| |
| test_is_empty<Empty>(); |
| test_is_empty<EmptyBase>(); |
| test_is_empty<StaticMember>(); |
| test_is_empty<bit_zero>(); |
| } |