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_ENABLE_IF_H
10 #define _LIBCPP___TYPE_TRAITS_ENABLE_IF_H
11 
12 #include <__config>
13 
14 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
15 #  pragma GCC system_header
16 #endif
17 
18 _LIBCPP_BEGIN_NAMESPACE_STD
19 
20 template <bool, class _Tp = void> struct _LIBCPP_TEMPLATE_VIS enable_if {};
21 template <class _Tp> struct _LIBCPP_TEMPLATE_VIS enable_if<true, _Tp> {typedef _Tp type;};
22 
23 template <bool _Bp, class _Tp = void> using __enable_if_t _LIBCPP_NODEBUG = typename enable_if<_Bp, _Tp>::type;
24 
25 #if _LIBCPP_STD_VER > 11
26 template <bool _Bp, class _Tp = void> using enable_if_t = typename enable_if<_Bp, _Tp>::type;
27 #endif
28 
29 _LIBCPP_END_NAMESPACE_STD
30 
31 #endif // _LIBCPP___TYPE_TRAITS_ENABLE_IF_H
32