1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef _LIBCPP___TYPE_TRAITS_IS_VALID_EXPANSION_H 10 #define _LIBCPP___TYPE_TRAITS_IS_VALID_EXPANSION_H 11 12 #include <__config> 13 #include <__type_traits/integral_constant.h> 14 15 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 16 # pragma GCC system_header 17 #endif 18 19 _LIBCPP_BEGIN_NAMESPACE_STD 20 21 template <template <class...> class _Templ, class... _Args, class = _Templ<_Args...> > 22 true_type __sfinae_test_impl(int); 23 template <template <class...> class, class...> 24 false_type __sfinae_test_impl(...); 25 26 template <template <class...> class _Templ, class... _Args> 27 using _IsValidExpansion _LIBCPP_NODEBUG = decltype(std::__sfinae_test_impl<_Templ, _Args...>(0)); 28 29 _LIBCPP_END_NAMESPACE_STD 30 31 #endif // _LIBCPP___TYPE_TRAITS_IS_VALID_EXPANSION_H 32