blob: b9d91fcf8fc80300f819ff88fbc59471a500a656 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
|
/* Copyright 2016-2017 Joaquin M Lopez Munoz.
* Distributed under the Boost Software License, Version 1.0.
* (See accompanying file LICENSE_1_0.txt or copy at
* http://www.boost.org/LICENSE_1_0.txt)
*
* See http://www.boost.org/libs/poly_collection for library home page.
*/
#ifndef BOOST_POLY_COLLECTION_DETAIL_IS_FINAL_HPP
#define BOOST_POLY_COLLECTION_DETAIL_IS_FINAL_HPP
#if defined(_MSC_VER)
#pragma once
#endif
#include <boost/type_traits/is_final.hpp>
#include <type_traits>
/* technique explained at
* http://bannalia.blogspot.com/2016/09/compile-time-checking-existence-of.html
*/
namespace boost{
namespace poly_collection{
namespace detail{
namespace is_final_fallback{
template<typename T> using is_final=boost::is_final<T>;
struct hook{};
}}}}
namespace std{
template<>
struct is_void< ::boost::poly_collection::detail::is_final_fallback::hook>:
std::false_type
{
template<typename T>
static constexpr bool is_final_f()
{
using namespace ::boost::poly_collection::detail::is_final_fallback;
return is_final<T>::value;
}
};
} /* namespace std */
namespace boost{
namespace poly_collection{
namespace detail{
template<typename T>
struct is_final:std::integral_constant<
bool,
std::is_void<is_final_fallback::hook>::template is_final_f<T>()
>{};
} /* namespace poly_collection::detail */
} /* namespace poly_collection */
} /* namespace boost */
#endif
|