• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright 2014 Google Inc. All rights reserved.
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 FRUIT_TYPE_INFO_H
18 #define FRUIT_TYPE_INFO_H
19 
20 #include <fruit/impl/meta/vector.h>
21 #include <fruit/impl/util/demangle_type_name.h>
22 #include <typeinfo>
23 
24 #include <vector>
25 
26 namespace fruit {
27 namespace impl {
28 
29 // Similar to std::type_index, but with a constexpr constructor and also storing the type size and alignment.
30 // Also guaranteed to be aligned, to allow storing a TypeInfo and 1 bit together in the size of a void*.
31 struct alignas(1) alignas(void*) TypeInfo {
32 
33   struct ConcreteTypeInfo {
34     // These fields are allowed to have dummy values for abstract types.
35     std::size_t type_size;
36     std::size_t type_alignment;
37     bool is_trivially_destructible;
38 
39 #if FRUIT_EXTRA_DEBUG
40     bool is_abstract;
41 #endif
42   };
43 
44   // This should only be used if RTTI is disabled. Use the other constructor if possible.
45   explicit constexpr TypeInfo(ConcreteTypeInfo concrete_type_info);
46 
47   constexpr TypeInfo(const std::type_info& info, ConcreteTypeInfo concrete_type_info);
48 
49   std::string name() const;
50 
51   size_t size() const;
52 
53   size_t alignment() const;
54 
55   bool isTriviallyDestructible() const;
56 
57 private:
58   // The std::type_info struct associated with the type, or nullptr if RTTI is disabled.
59   // This is only used for the type name.
60   const std::type_info* info;
61   ConcreteTypeInfo concrete_type_info;
62 };
63 
64 struct TypeId {
65   const TypeInfo* type_info;
66 
67   explicit operator std::string() const;
68 
69   bool operator==(TypeId x) const;
70   bool operator!=(TypeId x) const;
71   bool operator<(TypeId x) const;
72 };
73 
74 // Returns the TypeId for the type T.
75 // Multiple invocations for the same type return the same value.
76 // This has special support for types of the form Annotated<SomeAnnotation, SomeType>, it reports
77 // data for SomeType (except the name, that is "Annotated<SomeAnnotation, SomeType>").
78 template <typename T>
79 TypeId getTypeId();
80 
81 // A convenience function that returns an std::vector of TypeId values for the given meta-vector of types.
82 template <typename V>
83 std::vector<TypeId> getTypeIdsForList();
84 
85 } // namespace impl
86 } // namespace fruit
87 
88 #if FRUIT_EXTRA_DEBUG
89 
90 #include <ostream>
91 
92 namespace fruit {
93 namespace impl {
94 
95 inline std::ostream& operator<<(std::ostream& os, TypeId type);
96 
97 } // namespace impl
98 } // namespace fruit
99 
100 #endif // FRUIT_EXTRA_DEBUG
101 
102 namespace std {
103 
104 template <>
105 struct hash<fruit::impl::TypeId> {
106   std::size_t operator()(fruit::impl::TypeId type) const;
107 };
108 
109 } // namespace std
110 
111 #include <fruit/impl/util/type_info.defn.h>
112 
113 #endif // FRUIT_TYPE_INFO_H
114