LeechCraft  0.6.70-13729-g7046a9d2a7
Modular cross-platform feature rich live environment.
applicative.h
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29 
30 #pragma once
31 
32 #include <optional>
33 #include <boost/optional.hpp>
34 
35 namespace LC
36 {
37 namespace Util
38 {
39  template<typename Applicative>
41 
42  template<typename AF, typename AV>
43  using GSLResult_t = typename InstanceApplicative<AF>::template GSLResult<AV>::Type_t;
44 
45  template<template<typename...> class Applicative, typename... Args, typename T>
46  auto Pure (const T& v)
47  {
48  return InstanceApplicative<Applicative<Args..., T>>::Pure (v);
49  }
50 
51  template<typename Applicative, typename T>
52  auto Pure (const T& v) -> decltype (InstanceApplicative<Applicative>::Pure (v))
53  {
55  }
56 
57  template<typename AF, typename AV>
58  GSLResult_t<AF, AV> GSL (const AF& af, const AV& av)
59  {
60  return InstanceApplicative<AF>::GSL (af, av);
61  }
62 
63  template<typename AF, typename AV>
64  auto operator* (const AF& af, const AV& av) -> decltype (GSL (af, av))
65  {
66  return GSL (af, av);
67  }
68 
69  // Implementations
70  template<typename T>
71  struct InstanceApplicative<boost::optional<T>>
72  {
73  using Type_t = boost::optional<T>;
74 
75  template<typename>
76  struct GSLResult;
77 
78  template<typename V>
79  struct GSLResult<boost::optional<V>>
80  {
81  using Type_t = boost::optional<std::result_of_t<T (const V&)>>;
82  };
83 
84  template<typename U>
85  static boost::optional<U> Pure (const U& v)
86  {
87  return { v };
88  }
89 
90  template<typename AV>
91  static GSLResult_t<Type_t, AV> GSL (const Type_t& f, const AV& v)
92  {
93  if (!f || !v)
94  return {};
95 
96  return { (*f) (*v) };
97  }
98  };
99 
100  template<typename T>
101  struct InstanceApplicative<std::optional<T>>
102  {
103  using Type_t = std::optional<T>;
104 
105  template<typename>
106  struct GSLResult;
107 
108  template<typename V>
109  struct GSLResult<std::optional<V>>
110  {
111  using Type_t = std::optional<std::result_of_t<T (const V&)>>;
112  };
113 
114  template<typename U>
115  static std::optional<U> Pure (const U& v)
116  {
117  return { v };
118  }
119 
120  template<typename AV>
121  static GSLResult_t<Type_t, AV> GSL (const Type_t& f, const AV& v)
122  {
123  if (!f || !v)
124  return {};
125 
126  return { (*f) (*v) };
127  }
128  };
129 }
130 }
Definition: prelude.h:38
static GSLResult_t< Type_t, AV > GSL(const Type_t &f, const AV &v)
Definition: applicative.h:121
STL namespace.
auto Pure(const T &v)
Definition: applicative.h:46
static boost::optional< U > Pure(const U &v)
Definition: applicative.h:85
constexpr detail::ExprTree< detail::ExprType::LeafStaticPlaceholder, detail::MemberPtrs< Ptr > > f
Definition: oral.h:955
auto operator*(const AF &af, const AV &av) -> decltype(GSL(af, av))
Definition: applicative.h:64
typename InstanceApplicative< AF >::template GSLResult< AV >::Type_t GSLResult_t
Definition: applicative.h:43
static GSLResult_t< Type_t, AV > GSL(const Type_t &f, const AV &v)
Definition: applicative.h:91
auto Pure(const T &v) -> decltype(InstanceApplicative< Applicative >::Pure(v))
Definition: applicative.h:52
static std::optional< U > Pure(const U &v)
Definition: applicative.h:115
Definition: constants.h:35
GSLResult_t< AF, AV > GSL(const AF &af, const AV &av)
Definition: applicative.h:58