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| 1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. |
| 2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
| 3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
| 4 | 4 |
| 5 // A Tuple is a generic templatized container, similar in concept to std::pair | 5 // A Tuple is a generic templatized container, similar in concept to std::pair |
| 6 // and std::tuple. The convenient MakeTuple() function takes any number of | 6 // and std::tuple. The convenient MakeTuple() function takes any number of |
|
Nico
2016/06/02 16:56:18
This needs updating.
// Use std::tuple as tuple t
tzik
2016/06/03 04:44:19
Done.
| |
| 7 // arguments and will construct and return the appropriate Tuple object. The | 7 // arguments and will construct and return the appropriate Tuple object. The |
| 8 // functions DispatchToMethod and DispatchToFunction take a function pointer or | 8 // functions DispatchToMethod and DispatchToFunction take a function pointer or |
| 9 // instance and method pointer, and unpack a tuple into arguments to the call. | 9 // instance and method pointer, and unpack a tuple into arguments to the call. |
| 10 // | 10 // |
| 11 // Tuple elements are copied by value, and stored in the tuple. See the unit | 11 // Tuple elements are copied by value, and stored in the tuple. See the unit |
| 12 // tests for more details of how/when the values are copied. | 12 // tests for more details of how/when the values are copied. |
| 13 // | 13 // |
| 14 // Example usage: | 14 // Example usage: |
| 15 // // These two methods of creating a Tuple are identical. | 15 // // These two methods of creating a Tuple are identical. |
| 16 // Tuple<int, const char*> tuple_a(1, "wee"); | 16 // Tuple<int, const char*> tuple_a(1, "wee"); |
|
Nico
2016/06/02 16:56:18
std::tuple
tzik
2016/06/03 04:44:19
Done.
| |
| 17 // Tuple<int, const char*> tuple_b = MakeTuple(1, "wee"); | 17 // Tuple<int, const char*> tuple_b = MakeTuple(1, "wee"); |
| 18 // | 18 // |
| 19 // void SomeFunc(int a, const char* b) { } | 19 // void SomeFunc(int a, const char* b) { } |
| 20 // DispatchToFunction(&SomeFunc, tuple_a); // SomeFunc(1, "wee") | 20 // DispatchToFunction(&SomeFunc, tuple_a); // SomeFunc(1, "wee") |
| 21 // DispatchToFunction( | 21 // DispatchToFunction( |
| 22 // &SomeFunc, MakeTuple(10, "foo")); // SomeFunc(10, "foo") | 22 // &SomeFunc, MakeTuple(10, "foo")); // SomeFunc(10, "foo") |
| 23 // | 23 // |
| 24 // struct { void SomeMeth(int a, int b, int c) { } } foo; | 24 // struct { void SomeMeth(int a, int b, int c) { } } foo; |
| 25 // DispatchToMethod(&foo, &Foo::SomeMeth, MakeTuple(1, 2, 3)); | 25 // DispatchToMethod(&foo, &Foo::SomeMeth, MakeTuple(1, 2, 3)); |
| 26 // // foo->SomeMeth(1, 2, 3); | 26 // // foo->SomeMeth(1, 2, 3); |
| (...skipping 76 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... | |
| 103 | 103 |
| 104 template <size_t N, size_t... Ns> | 104 template <size_t N, size_t... Ns> |
| 105 struct MakeIndexSequenceImpl<N, Ns...> | 105 struct MakeIndexSequenceImpl<N, Ns...> |
| 106 : MakeIndexSequenceImpl<N - 1, N - 1, Ns...> {}; | 106 : MakeIndexSequenceImpl<N - 1, N - 1, Ns...> {}; |
| 107 | 107 |
| 108 #endif // defined(OS_WIN) && defined(_PREFAST_) | 108 #endif // defined(OS_WIN) && defined(_PREFAST_) |
| 109 | 109 |
| 110 template <size_t N> | 110 template <size_t N> |
| 111 using MakeIndexSequence = typename MakeIndexSequenceImpl<N>::Type; | 111 using MakeIndexSequence = typename MakeIndexSequenceImpl<N>::Type; |
| 112 | 112 |
| 113 // Tuple ----------------------------------------------------------------------- | |
| 114 // | |
| 115 // This set of classes is useful for bundling 0 or more heterogeneous data types | |
| 116 // into a single variable. The advantage of this is that it greatly simplifies | |
| 117 // function objects that need to take an arbitrary number of parameters; see | |
| 118 // RunnableMethod and IPC::MessageWithTuple. | |
| 119 // | |
| 120 // Tuple<> is supplied to act as a 'void' type. It can be used, for example, | |
| 121 // when dispatching to a function that accepts no arguments (see the | |
| 122 // Dispatchers below). | |
| 123 // Tuple<A> is rarely useful. One such use is when A is non-const ref that you | |
| 124 // want filled by the dispatchee, and the tuple is merely a container for that | |
| 125 // output (a "tier"). See MakeRefTuple and its usages. | |
| 126 | |
| 127 template <typename... Ts> | |
| 128 using Tuple = std::tuple<Ts...>; | |
| 129 | |
| 130 using std::get; | |
| 131 | |
| 132 // Tuple creators ------------------------------------------------------------- | |
| 133 // | |
| 134 // Helper functions for constructing tuples while inferring the template | |
| 135 // argument types. | |
| 136 | |
| 137 template <typename... Ts> | |
| 138 inline Tuple<Ts...> MakeTuple(const Ts&... arg) { | |
| 139 return Tuple<Ts...>(arg...); | |
| 140 } | |
| 141 | |
| 142 // The following set of helpers make what Boost refers to as "Tiers" - a tuple | |
| 143 // of references. | |
| 144 | |
| 145 template <typename... Ts> | |
| 146 inline Tuple<Ts&...> MakeRefTuple(Ts&... arg) { | |
| 147 return Tuple<Ts&...>(arg...); | |
| 148 } | |
| 149 | |
| 150 // Dispatchers ---------------------------------------------------------------- | 113 // Dispatchers ---------------------------------------------------------------- |
| 151 // | 114 // |
| 152 // Helper functions that call the given method on an object, with the unpacked | 115 // Helper functions that call the given method on an object, with the unpacked |
| 153 // tuple arguments. Notice that they all have the same number of arguments, | 116 // tuple arguments. Notice that they all have the same number of arguments, |
| 154 // so you need only write: | 117 // so you need only write: |
| 155 // DispatchToMethod(object, &Object::method, args); | 118 // DispatchToMethod(object, &Object::method, args); |
| 156 // This is very useful for templated dispatchers, since they don't need to know | 119 // This is very useful for templated dispatchers, since they don't need to know |
| 157 // what type |args| is. | 120 // what type |args| is. |
| 158 | 121 |
| 159 // Non-Static Dispatchers with no out params. | 122 // Non-Static Dispatchers with no out params. |
| 160 | 123 |
| 161 template <typename ObjT, typename Method, typename... Ts, size_t... Ns> | 124 template <typename ObjT, typename Method, typename... Ts, size_t... Ns> |
| 162 inline void DispatchToMethodImpl(const ObjT& obj, | 125 inline void DispatchToMethodImpl(const ObjT& obj, |
| 163 Method method, | 126 Method method, |
| 164 const Tuple<Ts...>& arg, | 127 const std::tuple<Ts...>& arg, |
| 165 IndexSequence<Ns...>) { | 128 IndexSequence<Ns...>) { |
| 166 (obj->*method)(internal::Unwrap(get<Ns>(arg))...); | 129 (obj->*method)(internal::Unwrap(std::get<Ns>(arg))...); |
| 167 } | 130 } |
| 168 | 131 |
| 169 template <typename ObjT, typename Method, typename... Ts> | 132 template <typename ObjT, typename Method, typename... Ts> |
| 170 inline void DispatchToMethod(const ObjT& obj, | 133 inline void DispatchToMethod(const ObjT& obj, |
| 171 Method method, | 134 Method method, |
| 172 const Tuple<Ts...>& arg) { | 135 const std::tuple<Ts...>& arg) { |
| 173 DispatchToMethodImpl(obj, method, arg, MakeIndexSequence<sizeof...(Ts)>()); | 136 DispatchToMethodImpl(obj, method, arg, MakeIndexSequence<sizeof...(Ts)>()); |
| 174 } | 137 } |
| 175 | 138 |
| 176 // Static Dispatchers with no out params. | 139 // Static Dispatchers with no out params. |
| 177 | 140 |
| 178 template <typename Function, typename... Ts, size_t... Ns> | 141 template <typename Function, typename... Ts, size_t... Ns> |
| 179 inline void DispatchToFunctionImpl(Function function, | 142 inline void DispatchToFunctionImpl(Function function, |
| 180 const Tuple<Ts...>& arg, | 143 const std::tuple<Ts...>& arg, |
| 181 IndexSequence<Ns...>) { | 144 IndexSequence<Ns...>) { |
| 182 (*function)(internal::Unwrap(get<Ns>(arg))...); | 145 (*function)(internal::Unwrap(std::get<Ns>(arg))...); |
| 183 } | 146 } |
| 184 | 147 |
| 185 template <typename Function, typename... Ts> | 148 template <typename Function, typename... Ts> |
| 186 inline void DispatchToFunction(Function function, const Tuple<Ts...>& arg) { | 149 inline void DispatchToFunction(Function function, |
| 150 const std::tuple<Ts...>& arg) { | |
| 187 DispatchToFunctionImpl(function, arg, MakeIndexSequence<sizeof...(Ts)>()); | 151 DispatchToFunctionImpl(function, arg, MakeIndexSequence<sizeof...(Ts)>()); |
| 188 } | 152 } |
| 189 | 153 |
| 190 // Dispatchers with out parameters. | 154 // Dispatchers with out parameters. |
| 191 | 155 |
| 192 template <typename ObjT, | 156 template <typename ObjT, |
| 193 typename Method, | 157 typename Method, |
| 194 typename... InTs, | 158 typename... InTs, |
| 195 typename... OutTs, | 159 typename... OutTs, |
| 196 size_t... InNs, | 160 size_t... InNs, |
| 197 size_t... OutNs> | 161 size_t... OutNs> |
| 198 inline void DispatchToMethodImpl(const ObjT& obj, | 162 inline void DispatchToMethodImpl(const ObjT& obj, |
| 199 Method method, | 163 Method method, |
| 200 const Tuple<InTs...>& in, | 164 const std::tuple<InTs...>& in, |
| 201 Tuple<OutTs...>* out, | 165 std::tuple<OutTs...>* out, |
| 202 IndexSequence<InNs...>, | 166 IndexSequence<InNs...>, |
| 203 IndexSequence<OutNs...>) { | 167 IndexSequence<OutNs...>) { |
| 204 (obj->*method)(internal::Unwrap(get<InNs>(in))..., &get<OutNs>(*out)...); | 168 (obj->*method)(internal::Unwrap(std::get<InNs>(in))..., |
| 169 &std::get<OutNs>(*out)...); | |
| 205 } | 170 } |
| 206 | 171 |
| 207 template <typename ObjT, typename Method, typename... InTs, typename... OutTs> | 172 template <typename ObjT, typename Method, typename... InTs, typename... OutTs> |
| 208 inline void DispatchToMethod(const ObjT& obj, | 173 inline void DispatchToMethod(const ObjT& obj, |
| 209 Method method, | 174 Method method, |
| 210 const Tuple<InTs...>& in, | 175 const std::tuple<InTs...>& in, |
| 211 Tuple<OutTs...>* out) { | 176 std::tuple<OutTs...>* out) { |
| 212 DispatchToMethodImpl(obj, method, in, out, | 177 DispatchToMethodImpl(obj, method, in, out, |
| 213 MakeIndexSequence<sizeof...(InTs)>(), | 178 MakeIndexSequence<sizeof...(InTs)>(), |
| 214 MakeIndexSequence<sizeof...(OutTs)>()); | 179 MakeIndexSequence<sizeof...(OutTs)>()); |
| 215 } | 180 } |
| 216 | 181 |
| 217 } // namespace base | 182 } // namespace base |
| 218 | 183 |
| 219 #endif // BASE_TUPLE_H_ | 184 #endif // BASE_TUPLE_H_ |
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