Intel(R) Threading Building Blocks Doxygen Documentation  version 4.2.3
_template_helpers.h
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1 /*
2  Copyright (c) 2005-2019 Intel Corporation
3 
4  Licensed under the Apache License, Version 2.0 (the "License");
5  you may not use this file except in compliance with the License.
6  You may obtain a copy of the License at
7 
8  http://www.apache.org/licenses/LICENSE-2.0
9 
10  Unless required by applicable law or agreed to in writing, software
11  distributed under the License is distributed on an "AS IS" BASIS,
12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  See the License for the specific language governing permissions and
14  limitations under the License.
15 */
16 
17 #ifndef __TBB_template_helpers_H
18 #define __TBB_template_helpers_H
19 
20 #include <utility>
21 #include <cstddef>
22 #include "../tbb_config.h"
23 #if __TBB_CPP11_VARIADIC_TEMPLATES_PRESENT && __TBB_CPP11_TEMPLATE_ALIASES_PRESENT
24 #include <type_traits>
25 #endif
26 #if __TBB_CPP11_PRESENT
27 #include <iterator>
28 #include <memory> // allocator_traits
29 #endif
30 
31 namespace tbb { namespace internal {
32 
34 template<bool Condition, typename T = void> struct enable_if {};
35 template<typename T> struct enable_if<true, T> { typedef T type; };
36 
38 template<typename T> struct strip { typedef T type; };
39 template<typename T> struct strip<const T> { typedef T type; };
40 template<typename T> struct strip<volatile T> { typedef T type; };
41 template<typename T> struct strip<const volatile T> { typedef T type; };
42 template<typename T> struct strip<T&> { typedef T type; };
43 template<typename T> struct strip<const T&> { typedef T type; };
44 template<typename T> struct strip<volatile T&> { typedef T type; };
45 template<typename T> struct strip<const volatile T&> { typedef T type; };
47 template<typename T> struct strip<T(&)()> { typedef T(*type)(); };
48 #if __TBB_CPP11_RVALUE_REF_PRESENT
49 template<typename T> struct strip<T&&> { typedef T type; };
50 template<typename T> struct strip<const T&&> { typedef T type; };
51 template<typename T> struct strip<volatile T&&> { typedef T type; };
52 template<typename T> struct strip<const volatile T&&> { typedef T type; };
53 #endif
54 template<typename T, std::size_t N> struct strip<T(&)[N]> { typedef T* type; };
56 template<typename T, std::size_t N> struct strip<const T(&)[N]> { typedef const T* type; };
57 template<typename T, std::size_t N> struct strip<volatile T(&)[N]> { typedef volatile T* type; };
58 template<typename T, std::size_t N> struct strip<const volatile T(&)[N]> { typedef const volatile T* type; };
59 
61 template<class U, class V> struct is_same_type { static const bool value = false; };
62 template<class W> struct is_same_type<W,W> { static const bool value = true; };
63 
64 template<typename T> struct is_ref { static const bool value = false; };
65 template<typename U> struct is_ref<U&> { static const bool value = true; };
66 
68 template<typename T> struct is_integral_impl { static const bool value = false; };
69 template<> struct is_integral_impl<bool> { static const bool value = true; };
70 template<> struct is_integral_impl<char> { static const bool value = true; };
71 #if __TBB_CPP11_PRESENT
72 template<> struct is_integral_impl<char16_t> { static const bool value = true; };
73 template<> struct is_integral_impl<char32_t> { static const bool value = true; };
74 #endif
75 template<> struct is_integral_impl<wchar_t> { static const bool value = true; };
76 template<> struct is_integral_impl<short> { static const bool value = true; };
77 template<> struct is_integral_impl<int> { static const bool value = true; };
78 template<> struct is_integral_impl<long> { static const bool value = true; };
79 template<> struct is_integral_impl<long long> { static const bool value = true; };
80 
81 template<typename T>
82 struct is_integral : is_integral_impl<typename strip<T>::type> {};
83 
84 #if __TBB_CPP11_VARIADIC_TEMPLATES_PRESENT
85 template<typename...> struct void_t { typedef void type; };
87 #endif
88 
89 #if __TBB_CPP11_VARIADIC_TEMPLATES_PRESENT && __TBB_CPP11_TEMPLATE_ALIASES_PRESENT
90 
91 // Generic SFINAE helper for expression checks, based on the idea demonstrated in ISO C++ paper n4502
92 template<typename T, typename, template<typename> class... Checks>
93 struct supports_impl { typedef std::false_type type; };
94 template<typename T, template<typename> class... Checks>
95 struct supports_impl<T, typename void_t<Checks<T>...>::type, Checks...> { typedef std::true_type type; };
96 
97 template<typename T, template<typename> class... Checks>
98 using supports = typename supports_impl<T, void, Checks...>::type;
99 
100 #endif /* __TBB_CPP11_VARIADIC_TEMPLATES_PRESENT && __TBB_CPP11_TEMPLATE_ALIASES_PRESENT */
101 
102 #if __TBB_CPP11_RVALUE_REF_PRESENT && __TBB_CPP11_VARIADIC_TEMPLATES_PRESENT
103 
105 template< typename... Types >
106 struct stored_pack;
107 
108 template<>
109 struct stored_pack<>
110 {
113 
114  // Friend front-end functions
115  template< typename F, typename Pack > friend void call( F&& f, Pack&& p );
116  template< typename Ret, typename F, typename Pack > friend Ret call_and_return( F&& f, Pack&& p );
117 
118 protected:
119  // Ideally, ref-qualified non-static methods would be used,
120  // but that would greatly reduce the set of compilers where it works.
121  template< typename Ret, typename F, typename... Preceding >
122  static Ret call( F&& f, const pack_type& /*pack*/, Preceding&&... params ) {
123  return std::forward<F>(f)( std::forward<Preceding>(params)... );
124  }
125  template< typename Ret, typename F, typename... Preceding >
126  static Ret call( F&& f, pack_type&& /*pack*/, Preceding&&... params ) {
127  return std::forward<F>(f)( std::forward<Preceding>(params)... );
128  }
129 };
130 
131 template< typename T, typename... Types >
132 struct stored_pack<T, Types...> : stored_pack<Types...>
133 {
134  typedef stored_pack<T, Types...> pack_type;
135  typedef stored_pack<Types...> pack_remainder;
136  // Since lifetime of original values is out of control, copies should be made.
137  // Thus references should be stripped away from the deduced type.
139 
140  // Here rvalue references act in the same way as forwarding references,
141  // as long as class template parameters were deduced via forwarding references.
142  stored_pack( T&& t, Types&&... types )
143  : pack_remainder(std::forward<Types>(types)...), leftmost_value(std::forward<T>(t)) {}
144 
145  // Friend front-end functions
146  template< typename F, typename Pack > friend void call( F&& f, Pack&& p );
147  template< typename Ret, typename F, typename Pack > friend Ret call_and_return( F&& f, Pack&& p );
148 
149 protected:
150  template< typename Ret, typename F, typename... Preceding >
151  static Ret call( F&& f, pack_type& pack, Preceding&&... params ) {
152  return pack_remainder::template call<Ret>(
153  std::forward<F>(f), static_cast<pack_remainder&>(pack),
154  std::forward<Preceding>(params)... , pack.leftmost_value
155  );
156  }
157  template< typename Ret, typename F, typename... Preceding >
158  static Ret call( F&& f, const pack_type& pack, Preceding&&... params ) {
159  return pack_remainder::template call<Ret>(
160  std::forward<F>(f), static_cast<const pack_remainder&>(pack),
161  std::forward<Preceding>(params)... , pack.leftmost_value
162  );
163  }
164  template< typename Ret, typename F, typename... Preceding >
165  static Ret call( F&& f, pack_type&& pack, Preceding&&... params ) {
166  return pack_remainder::template call<Ret>(
167  std::forward<F>(f), static_cast<pack_remainder&&>(pack),
168  std::forward<Preceding>(params)... , std::move(pack.leftmost_value)
169  );
170  }
171 };
172 
174 template< typename F, typename Pack >
175 void call( F&& f, Pack&& p ) {
176  strip<Pack>::type::template call<void>( std::forward<F>(f), std::forward<Pack>(p) );
177 }
178 
179 template< typename Ret, typename F, typename Pack >
180 Ret call_and_return( F&& f, Pack&& p ) {
181  return strip<Pack>::type::template call<Ret>( std::forward<F>(f), std::forward<Pack>(p) );
182 }
183 
184 template< typename... Types >
185 stored_pack<Types...> save_pack( Types&&... types ) {
186  return stored_pack<Types...>( std::forward<Types>(types)... );
187 }
188 
189 #endif /* __TBB_CPP11_RVALUE_REF_PRESENT && __TBB_CPP11_VARIADIC_TEMPLATES_PRESENT */
190 
191 #if __TBB_CPP14_INTEGER_SEQUENCE_PRESENT
192 
193 using std::index_sequence;
195 
196 #elif __TBB_CPP11_VARIADIC_TEMPLATES_PRESENT && __TBB_CPP11_TEMPLATE_ALIASES_PRESENT
197 
198 template<std::size_t... S> class index_sequence {};
199 
200 template<std::size_t N, std::size_t... S>
201 struct make_index_sequence_impl : make_index_sequence_impl < N - 1, N - 1, S... > {};
202 
203 template<std::size_t... S>
204 struct make_index_sequence_impl <0, S...> {
205  using type = index_sequence<S...>;
206 };
207 
208 template<std::size_t N>
210 
211 #endif /* __TBB_CPP14_INTEGER_SEQUENCE_PRESENT */
212 
213 #if __TBB_CPP11_PRESENT
214 
215 template< typename Iter >
216 using iterator_value_t = typename std::iterator_traits<Iter>::value_type;
217 
218 template< typename Iter >
219 using iterator_key_t = typename std::remove_const<typename iterator_value_t<Iter>::first_type>::type;
220 
221 template< typename Iter >
222 using iterator_mapped_t = typename iterator_value_t<Iter>::second_type;
223 
224 template< typename A > using value_type = typename A::value_type;
225 template< typename A > using alloc_ptr_t = typename std::allocator_traits<A>::pointer;
226 template< typename A > using has_allocate = decltype(std::declval<alloc_ptr_t<A>&>() = std::declval<A>().allocate(0));
227 template< typename A > using has_deallocate = decltype(std::declval<A>().deallocate(std::declval<alloc_ptr_t<A>>(), 0));
228 
229 // value_type should be checked first because it can be used in other checks (via allocator_traits)
230 template< typename T >
232 
233 #if __TBB_CPP14_VARIABLE_TEMPLATES_PRESENT
234 
235 template< typename T >
236 static constexpr bool is_allocator_v = is_allocator<T>::value;
237 
238 #endif /*__TBB_CPP14_VARIABLE_TEMPLATES */
239 
240 template< std::size_t N, typename... Args >
241 struct pack_element {
242  using type = void;
243 };
244 
245 template< std::size_t N, typename T, typename... Args >
246 struct pack_element<N, T, Args...> {
247  using type = typename pack_element<N - 1, Args...>::type;
248 };
249 
250 template< typename T, typename... Args >
251 struct pack_element<0, T, Args...> {
252  using type = T;
253 };
254 
255 template< std::size_t N, typename... Args >
256 using pack_element_t = typename pack_element<N, Args...>::type;
257 
258 template <typename Comp> using is_transparent = typename Comp::is_transparent;
259 
260 template <typename Comp>
261 using has_is_transparent = supports<Comp, is_transparent>;
262 
263 #endif /* __TBB_CPP11_PRESENT */
264 
265 } } // namespace internal, namespace tbb
266 
267 #endif /* __TBB_template_helpers_H */
stored_pack< Types... > save_pack(Types &&... types)
bool_constant< false > false_type
Definition: tbb_stddef.h:469
Ret call_and_return(F &&f, Pack &&p)
typename tbb::internal::make_index_sequence_impl< N >::type make_index_sequence
void call(F &&f, Pack &&p)
Calls the given function with arguments taken from a stored_pack.
The graph class.
Partial support for std::is_integral.
static Ret call(F &&f, const pack_type &, Preceding &&... params)
void const char const char int ITT_FORMAT __itt_group_sync x void const char ITT_FORMAT __itt_group_sync s void ITT_FORMAT __itt_group_sync p void ITT_FORMAT p void ITT_FORMAT p no args __itt_suppress_mode_t unsigned int void size_t ITT_FORMAT d void ITT_FORMAT p void ITT_FORMAT p __itt_model_site __itt_model_site_instance ITT_FORMAT p __itt_model_task __itt_model_task_instance ITT_FORMAT p void ITT_FORMAT p void ITT_FORMAT p void size_t ITT_FORMAT d void ITT_FORMAT p const wchar_t ITT_FORMAT s const char ITT_FORMAT s const char ITT_FORMAT s const char ITT_FORMAT s no args void ITT_FORMAT p size_t ITT_FORMAT d no args const wchar_t const wchar_t ITT_FORMAT s __itt_heap_function void size_t int ITT_FORMAT d __itt_heap_function void ITT_FORMAT p __itt_heap_function void void size_t int ITT_FORMAT d no args no args unsigned int ITT_FORMAT u const __itt_domain __itt_id ITT_FORMAT lu const __itt_domain __itt_id __itt_id __itt_string_handle ITT_FORMAT p const __itt_domain __itt_id ITT_FORMAT p const __itt_domain __itt_id __itt_timestamp __itt_timestamp ITT_FORMAT lu const __itt_domain __itt_id __itt_id __itt_string_handle ITT_FORMAT p const __itt_domain ITT_FORMAT p const __itt_domain __itt_string_handle unsigned long long ITT_FORMAT lu const __itt_domain __itt_id __itt_string_handle __itt_metadata_type size_t void ITT_FORMAT p const __itt_domain __itt_id __itt_string_handle const wchar_t size_t ITT_FORMAT lu const __itt_domain __itt_id __itt_relation __itt_id ITT_FORMAT p const wchar_t int ITT_FORMAT __itt_group_mark S
void const char const char int ITT_FORMAT __itt_group_sync x void const char ITT_FORMAT __itt_group_sync s void ITT_FORMAT __itt_group_sync p void ITT_FORMAT p void ITT_FORMAT p no args __itt_suppress_mode_t unsigned int void size_t ITT_FORMAT d void ITT_FORMAT p void ITT_FORMAT p __itt_model_site __itt_model_site_instance ITT_FORMAT p __itt_model_task __itt_model_task_instance ITT_FORMAT p void ITT_FORMAT p void ITT_FORMAT p void size_t ITT_FORMAT d void ITT_FORMAT p const wchar_t ITT_FORMAT s const char ITT_FORMAT s const char ITT_FORMAT s const char ITT_FORMAT s no args void ITT_FORMAT p size_t ITT_FORMAT d no args const wchar_t const wchar_t ITT_FORMAT s __itt_heap_function void size_t int ITT_FORMAT d __itt_heap_function void ITT_FORMAT p __itt_heap_function void void size_t int ITT_FORMAT d no args no args unsigned int ITT_FORMAT u const __itt_domain __itt_id ITT_FORMAT lu const __itt_domain __itt_id __itt_id __itt_string_handle ITT_FORMAT p const __itt_domain __itt_id ITT_FORMAT p const __itt_domain __itt_id __itt_timestamp __itt_timestamp ITT_FORMAT lu const __itt_domain __itt_id __itt_id __itt_string_handle ITT_FORMAT p const __itt_domain ITT_FORMAT p const __itt_domain __itt_string_handle unsigned long long value
static Ret call(F &&f, pack_type &&, Preceding &&... params)
static const bool value
static Ret call(F &&f, const pack_type &pack, Preceding &&... params)
void move(tbb_thread &t1, tbb_thread &t2)
Definition: tbb_thread.h:305
Enables one or the other code branches.
Detects whether two given types are the same.
Strips its template type argument from cv- and ref-qualifiers.
Allows to store a function parameter pack as a variable and later pass it to another function.
std::void_t internal implementation (to avoid GCC < 4.7 "template aliases" absence)
typename supports_impl< T, void, Checks... >::type supports
void const char const char int ITT_FORMAT __itt_group_sync x void const char ITT_FORMAT __itt_group_sync s void ITT_FORMAT __itt_group_sync p void ITT_FORMAT p void ITT_FORMAT p no args __itt_suppress_mode_t unsigned int void size_t ITT_FORMAT d void ITT_FORMAT p void ITT_FORMAT p __itt_model_site __itt_model_site_instance ITT_FORMAT p __itt_model_task __itt_model_task_instance ITT_FORMAT p void ITT_FORMAT p void ITT_FORMAT p void size_t ITT_FORMAT d void ITT_FORMAT p const wchar_t ITT_FORMAT s const char ITT_FORMAT s const char ITT_FORMAT s const char ITT_FORMAT s no args void ITT_FORMAT p size_t ITT_FORMAT d no args const wchar_t const wchar_t ITT_FORMAT s __itt_heap_function void size_t int ITT_FORMAT d __itt_heap_function void ITT_FORMAT p __itt_heap_function void void size_t int ITT_FORMAT d no args no args unsigned int ITT_FORMAT u const __itt_domain __itt_id ITT_FORMAT lu const __itt_domain __itt_id __itt_id __itt_string_handle ITT_FORMAT p const __itt_domain __itt_id ITT_FORMAT p const __itt_domain __itt_id __itt_timestamp __itt_timestamp ITT_FORMAT lu const __itt_domain __itt_id __itt_id __itt_string_handle ITT_FORMAT p const __itt_domain ITT_FORMAT p const __itt_domain __itt_string_handle unsigned long long ITT_FORMAT lu const __itt_domain __itt_id __itt_string_handle __itt_metadata_type size_t void ITT_FORMAT p const __itt_domain __itt_id __itt_string_handle const wchar_t size_t ITT_FORMAT lu const __itt_domain __itt_id __itt_relation __itt_id ITT_FORMAT p const wchar_t int ITT_FORMAT __itt_group_mark d int
void const char const char int ITT_FORMAT __itt_group_sync p
static Ret call(F &&f, pack_type &&pack, Preceding &&... params)
static Ret call(F &&f, pack_type &pack, Preceding &&... params)
void const char const char int ITT_FORMAT __itt_group_sync x void const char ITT_FORMAT __itt_group_sync s void ITT_FORMAT __itt_group_sync p void ITT_FORMAT p void ITT_FORMAT p no args __itt_suppress_mode_t unsigned int void size_t ITT_FORMAT d void ITT_FORMAT p void ITT_FORMAT p __itt_model_site __itt_model_site_instance ITT_FORMAT p __itt_model_task __itt_model_task_instance ITT_FORMAT p void ITT_FORMAT p void ITT_FORMAT p void size_t ITT_FORMAT d void ITT_FORMAT p const wchar_t ITT_FORMAT s const char ITT_FORMAT s const char ITT_FORMAT s const char ITT_FORMAT s no args void ITT_FORMAT p size_t ITT_FORMAT d no args const wchar_t const wchar_t ITT_FORMAT s __itt_heap_function void size_t int ITT_FORMAT d __itt_heap_function void ITT_FORMAT p __itt_heap_function void void size_t int ITT_FORMAT d no args no args unsigned int ITT_FORMAT u const __itt_domain __itt_id ITT_FORMAT lu const __itt_domain __itt_id __itt_id __itt_string_handle ITT_FORMAT p const __itt_domain __itt_id ITT_FORMAT p const __itt_domain __itt_id __itt_timestamp __itt_timestamp ITT_FORMAT lu const __itt_domain __itt_id __itt_id __itt_string_handle ITT_FORMAT p const __itt_domain ITT_FORMAT p const __itt_domain __itt_string_handle unsigned long long ITT_FORMAT lu const __itt_domain __itt_id __itt_string_handle __itt_metadata_type type
bool_constant< true > true_type
Definition: tbb_stddef.h:468

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