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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20, c++23
// These compilers don't support __builtin_is_virtual_base_of yet.
// UNSUPPORTED: clang-18, clang-19, gcc-14, apple-clang-16, apple-clang-17
// <type_traits>
// std::is_virtual_base_of
#include <type_traits>
#include <cassert>
template <bool expected, class Base, class Derived>
void test() {
// Test the type of the variables
{
static_assert(std::is_same_v<bool const, decltype(std::is_virtual_base_of<Base, Derived>::value)>);
static_assert(std::is_same_v<bool const, decltype(std::is_virtual_base_of_v<Base, Derived>)>);
}
// Test their value
{
static_assert(std::is_virtual_base_of<Base, Derived>::value == expected);
static_assert(std::is_virtual_base_of<const Base, Derived>::value == expected);
static_assert(std::is_virtual_base_of<Base, const Derived>::value == expected);
static_assert(std::is_virtual_base_of<const Base, const Derived>::value == expected);
static_assert(std::is_virtual_base_of_v<Base, Derived> == expected);
static_assert(std::is_virtual_base_of_v<const Base, Derived> == expected);
static_assert(std::is_virtual_base_of_v<Base, const Derived> == expected);
static_assert(std::is_virtual_base_of_v<const Base, const Derived> == expected);
}
// Check the relationship with is_base_of. If it's not a base of, it can't be a virtual base of.
{ static_assert(!std::is_base_of_v<Base, Derived> ? !std::is_virtual_base_of_v<Base, Derived> : true); }
// Make sure they can be referenced at runtime
{
bool const& a = std::is_virtual_base_of<Base, Derived>::value;
bool const& b = std::is_virtual_base_of_v<Base, Derived>;
assert(a == expected);
assert(b == expected);
}
}
struct Incomplete;
struct Unrelated {};
union IncompleteUnion;
union Union {
int i;
float f;
};
class Base {};
class Derived : Base {};
class Derived2 : Base {};
class Derived2a : Derived {};
class Derived2b : Derived {};
class Derived3Virtual : virtual Derived2a, virtual Derived2b {};
struct DerivedTransitiveViaNonVirtual : Derived3Virtual {};
struct DerivedTransitiveViaVirtual : virtual Derived3Virtual {};
template <typename T>
struct CrazyDerived : T {};
template <typename T>
struct CrazyDerivedVirtual : virtual T {};
struct DerivedPrivate : private virtual Base {};
struct DerivedProtected : protected virtual Base {};
struct DerivedPrivatePrivate : private DerivedPrivate {};
struct DerivedPrivateProtected : private DerivedProtected {};
struct DerivedProtectedPrivate : protected DerivedProtected {};
struct DerivedProtectedProtected : protected DerivedProtected {};
struct DerivedTransitivePrivate : private Derived, private Derived2 {};
int main(int, char**) {
// Test with non-virtual inheritance
{
test<false, Base, Base>();
test<false, Base, Derived>();
test<false, Base, Derived2>();
test<false, Derived, DerivedTransitivePrivate>();
test<false, Derived, Base>();
test<false, Incomplete, Derived>();
// Derived must be a complete type if Base and Derived are non-union class types
// test<false, Base, Incomplete>();
}
// Test with virtual inheritance
{
test<false, Base, Derived3Virtual>();
test<false, Derived, Derived3Virtual>();
test<true, Derived2b, Derived3Virtual>();
test<true, Derived2a, Derived3Virtual>();
test<true, Base, DerivedPrivate>();
test<true, Base, DerivedProtected>();
test<true, Base, DerivedPrivatePrivate>();
test<true, Base, DerivedPrivateProtected>();
test<true, Base, DerivedProtectedPrivate>();
test<true, Base, DerivedProtectedProtected>();
test<true, Derived2a, DerivedTransitiveViaNonVirtual>();
test<true, Derived2b, DerivedTransitiveViaNonVirtual>();
test<true, Derived2a, DerivedTransitiveViaVirtual>();
test<true, Derived2b, DerivedTransitiveViaVirtual>();
test<false, Base, CrazyDerived<Base>>();
test<false, CrazyDerived<Base>, Base>();
test<true, Base, CrazyDerivedVirtual<Base>>();
test<false, CrazyDerivedVirtual<Base>, Base>();
}
// Test unrelated types
{
test<false, Base&, Derived&>();
test<false, Base[3], Derived[3]>();
test<false, Unrelated, Derived>();
test<false, Base, Unrelated>();
test<false, Base, void>();
test<false, void, Derived>();
}
// Test scalar types
{
test<false, int, Base>();
test<false, int, Derived>();
test<false, int, Incomplete>();
test<false, int, int>();
test<false, Base, int>();
test<false, Derived, int>();
test<false, Incomplete, int>();
test<false, int[], int[]>();
test<false, long, int>();
test<false, int, long>();
}
// Test unions
{
test<false, Union, Union>();
test<false, IncompleteUnion, IncompleteUnion>();
test<false, Union, IncompleteUnion>();
test<false, IncompleteUnion, Union>();
test<false, Incomplete, IncompleteUnion>();
test<false, IncompleteUnion, Incomplete>();
test<false, Unrelated, IncompleteUnion>();
test<false, IncompleteUnion, Unrelated>();
test<false, int, IncompleteUnion>();
test<false, IncompleteUnion, int>();
test<false, Unrelated, Union>();
test<false, Union, Unrelated>();
test<false, int, Unrelated>();
test<false, Union, int>();
}
return 0;
}
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