LeechCraft  0.6.70-6645-gcd10d7e
Modular cross-platform feature rich live environment.
visitor.h
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29 
30 #pragma once
31 
32 #include <boost/variant.hpp>
33 
34 namespace LeechCraft
35 {
36 namespace Util
37 {
38  namespace detail
39  {
40  template<typename Head, typename... Tail>
41  struct VisitorBase : Head, VisitorBase<Tail...>
42  {
43  using Head::operator();
45 
46  VisitorBase (Head&& head, Tail&&... tail)
47  : Head { std::forward<Head> (head) }
48  , VisitorBase<Tail...> { std::forward<Tail> (tail)... }
49  {
50  }
51  };
52 
53  template<typename Head>
54  struct VisitorBase<Head> : Head
55  {
56  using Head::operator();
57 
58  VisitorBase (Head&& head)
59  : Head { std::forward<Head> (head) }
60  {
61  }
62  };
63 
64  template<typename R, typename... Args>
65  struct Visitor : boost::static_visitor<R>, VisitorBase<Args...>
66  {
67  using VisitorBase<Args...>::VisitorBase;
68  };
69  }
70 
71  template<typename HeadVar, typename... TailVars, typename... Args>
72  auto Visit (const boost::variant<HeadVar, TailVars...>& v, Args&&... args) ->
73  decltype (detail::VisitorBase<Args...> { std::forward<Args> (args)... } (std::declval<HeadVar> ()))
74  {
75  using R_t = decltype (detail::VisitorBase<Args...> { std::forward<Args> (args)... } (std::declval<HeadVar> ()));
76 
77  return boost::apply_visitor (detail::Visitor<R_t, Args...> { std::forward<Args> (args)... }, v);
78  }
79 
80  template<typename T, typename... Args>
81  auto InvokeOn (T&& t, Args&&... args) -> decltype (detail::VisitorBase<Args...> { std::forward<Args> (args)... } (std::forward<T> (t)))
82  {
83  return detail::VisitorBase<Args...> { std::forward<Args> (args)... } (std::forward<T> (t));
84  }
85 }
86 }
constexpr List< T... > Tail(List< H, T... >)
Definition: typelist.h:44
VisitorBase(Head &&head, Tail &&...tail)
Definition: visitor.h:46
auto Visit(const boost::variant< HeadVar, TailVars... > &v, Args &&...args) -> decltype(detail::VisitorBase< Args... >
Definition: visitor.h:72
auto InvokeOn(T &&t, Args &&...args) -> decltype(detail::VisitorBase< Args... >
Definition: visitor.h:81