blob: b59b6f5a6a2f31bb19bc90b80bf1249a91724523 (
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
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
|
//-----------------------------------------------------------------------------
// boost variant/static_visitor.hpp header file
// See http://www.boost.org for updates, documentation, and revision history.
//-----------------------------------------------------------------------------
//
// Copyright (c) 2002-2003
// Eric Friedman
//
// 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)
#ifndef BOOST_VARIANT_STATIC_VISITOR_HPP
#define BOOST_VARIANT_STATIC_VISITOR_HPP
#include "boost/config.hpp"
#include "boost/detail/workaround.hpp"
#include "boost/mpl/if.hpp"
#include "boost/type_traits/is_base_and_derived.hpp"
#if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
# include "boost/type_traits/is_same.hpp"
#endif
// should be the last #include
#include "boost/type_traits/detail/bool_trait_def.hpp"
namespace boost {
//////////////////////////////////////////////////////////////////////////
// class template static_visitor
//
// An empty base class that typedefs the return type of a deriving static
// visitor. The class is analogous to std::unary_function in this role.
//
namespace detail {
struct is_static_visitor_tag { };
typedef void static_visitor_default_return;
} // namespace detail
template <typename R = ::boost::detail::static_visitor_default_return>
class static_visitor
: public detail::is_static_visitor_tag
{
public: // typedefs
typedef R result_type;
protected: // for use as base class only
static_visitor() { }
~static_visitor() { }
};
//////////////////////////////////////////////////////////////////////////
// metafunction is_static_visitor
//
// Value metafunction indicates whether the specified type derives from
// static_visitor<...>.
//
// NOTE #1: This metafunction does NOT check whether the specified type
// fulfills the requirements of the StaticVisitor concept.
//
// NOTE #2: This template never needs to be specialized!
//
namespace detail {
template <typename T>
struct is_static_visitor_impl
{
BOOST_STATIC_CONSTANT(bool, value =
(::boost::is_base_and_derived<
detail::is_static_visitor_tag,
T
>::value));
};
} // namespace detail
BOOST_TT_AUX_BOOL_TRAIT_DEF1(
is_static_visitor
, T
, (::boost::detail::is_static_visitor_impl<T>::value)
)
} // namespace boost
#include "boost/type_traits/detail/bool_trait_undef.hpp"
#endif // BOOST_VARIANT_STATIC_VISITOR_HPP
|
Swift