blob: 1265fa15fe35c60a8c5f7bc0a3c0e13c0be77eb5 [file] [log] [blame]
Dominik Laskowski0bacf272020-10-22 14:08:27 -07001/*
2 * Copyright 2020 The Android Open Source Project
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#pragma once
18
19#include <algorithm>
20#include <iterator>
21#include <new>
Dominik Laskowskiccd50a42020-10-30 19:56:38 -070022#include <type_traits>
Dominik Laskowski0bacf272020-10-22 14:08:27 -070023
24#define FTL_ARRAY_TRAIT(T, U) using U = typename ArrayTraits<T>::U
25
26namespace android::ftl {
27
28template <typename T>
29struct ArrayTraits {
Dominik Laskowskie21dbed2020-12-04 20:51:43 -080030 using value_type = T;
31 using size_type = std::size_t;
32 using difference_type = std::ptrdiff_t;
Dominik Laskowski0bacf272020-10-22 14:08:27 -070033
Dominik Laskowskie21dbed2020-12-04 20:51:43 -080034 using pointer = value_type*;
35 using reference = value_type&;
36 using iterator = pointer;
37 using reverse_iterator = std::reverse_iterator<iterator>;
Dominik Laskowski0bacf272020-10-22 14:08:27 -070038
Dominik Laskowskie21dbed2020-12-04 20:51:43 -080039 using const_pointer = const value_type*;
40 using const_reference = const value_type&;
41 using const_iterator = const_pointer;
42 using const_reverse_iterator = std::reverse_iterator<const_iterator>;
Dominik Laskowski0bacf272020-10-22 14:08:27 -070043
Dominik Laskowskie21dbed2020-12-04 20:51:43 -080044 template <typename... Args>
45 static pointer construct_at(const_iterator it, Args&&... args) {
46 void* const ptr = const_cast<void*>(static_cast<const void*>(it));
47 if constexpr (std::is_constructible_v<value_type, Args...>) {
48 // TODO: Replace with std::construct_at in C++20.
49 return new (ptr) value_type(std::forward<Args>(args)...);
50 } else {
51 // Fall back to list initialization.
52 return new (ptr) value_type{std::forward<Args>(args)...};
Dominik Laskowski0bacf272020-10-22 14:08:27 -070053 }
Dominik Laskowskie21dbed2020-12-04 20:51:43 -080054 }
Dominik Laskowski0bacf272020-10-22 14:08:27 -070055};
56
57// CRTP mixin to define iterator functions in terms of non-const Self::begin and Self::end.
58template <typename Self, typename T>
59class ArrayIterators {
Dominik Laskowskie21dbed2020-12-04 20:51:43 -080060 FTL_ARRAY_TRAIT(T, size_type);
Dominik Laskowski0bacf272020-10-22 14:08:27 -070061
Dominik Laskowskie21dbed2020-12-04 20:51:43 -080062 FTL_ARRAY_TRAIT(T, reference);
63 FTL_ARRAY_TRAIT(T, iterator);
64 FTL_ARRAY_TRAIT(T, reverse_iterator);
Dominik Laskowski0bacf272020-10-22 14:08:27 -070065
Dominik Laskowskie21dbed2020-12-04 20:51:43 -080066 FTL_ARRAY_TRAIT(T, const_reference);
67 FTL_ARRAY_TRAIT(T, const_iterator);
68 FTL_ARRAY_TRAIT(T, const_reverse_iterator);
Dominik Laskowski0bacf272020-10-22 14:08:27 -070069
Dominik Laskowskie21dbed2020-12-04 20:51:43 -080070 Self& self() const { return *const_cast<Self*>(static_cast<const Self*>(this)); }
Dominik Laskowski0bacf272020-10-22 14:08:27 -070071
Dominik Laskowskie21dbed2020-12-04 20:51:43 -080072 public:
73 const_iterator begin() const { return cbegin(); }
74 const_iterator cbegin() const { return self().begin(); }
Dominik Laskowski0bacf272020-10-22 14:08:27 -070075
Dominik Laskowskie21dbed2020-12-04 20:51:43 -080076 const_iterator end() const { return cend(); }
77 const_iterator cend() const { return self().end(); }
Dominik Laskowski0bacf272020-10-22 14:08:27 -070078
Dominik Laskowskie21dbed2020-12-04 20:51:43 -080079 reverse_iterator rbegin() { return std::make_reverse_iterator(self().end()); }
80 const_reverse_iterator rbegin() const { return crbegin(); }
81 const_reverse_iterator crbegin() const { return self().rbegin(); }
Dominik Laskowski0bacf272020-10-22 14:08:27 -070082
Dominik Laskowskie21dbed2020-12-04 20:51:43 -080083 reverse_iterator rend() { return std::make_reverse_iterator(self().begin()); }
84 const_reverse_iterator rend() const { return crend(); }
85 const_reverse_iterator crend() const { return self().rend(); }
Dominik Laskowski0bacf272020-10-22 14:08:27 -070086
Dominik Laskowskie21dbed2020-12-04 20:51:43 -080087 iterator last() { return self().end() - 1; }
88 const_iterator last() const { return self().last(); }
Dominik Laskowski0bacf272020-10-22 14:08:27 -070089
Dominik Laskowskie21dbed2020-12-04 20:51:43 -080090 reference front() { return *self().begin(); }
91 const_reference front() const { return self().front(); }
Dominik Laskowski0bacf272020-10-22 14:08:27 -070092
Dominik Laskowskie21dbed2020-12-04 20:51:43 -080093 reference back() { return *last(); }
94 const_reference back() const { return self().back(); }
Dominik Laskowski0bacf272020-10-22 14:08:27 -070095
Dominik Laskowskie21dbed2020-12-04 20:51:43 -080096 reference operator[](size_type i) { return *(self().begin() + i); }
97 const_reference operator[](size_type i) const { return self()[i]; }
Dominik Laskowski0bacf272020-10-22 14:08:27 -070098};
99
100// Mixin to define comparison operators for an array-like template.
101// TODO: Replace with operator<=> in C++20.
Dominik Laskowski5444fc82020-11-24 13:41:10 -0800102template <template <typename, std::size_t> class Array>
Dominik Laskowski0bacf272020-10-22 14:08:27 -0700103struct ArrayComparators {
Dominik Laskowskie21dbed2020-12-04 20:51:43 -0800104 template <typename T, std::size_t N, std::size_t M>
105 friend bool operator==(const Array<T, N>& lhs, const Array<T, M>& rhs) {
106 return lhs.size() == rhs.size() && std::equal(lhs.begin(), lhs.end(), rhs.begin());
107 }
Dominik Laskowski0bacf272020-10-22 14:08:27 -0700108
Dominik Laskowskie21dbed2020-12-04 20:51:43 -0800109 template <typename T, std::size_t N, std::size_t M>
110 friend bool operator<(const Array<T, N>& lhs, const Array<T, M>& rhs) {
111 return std::lexicographical_compare(lhs.begin(), lhs.end(), rhs.begin(), rhs.end());
112 }
Dominik Laskowski0bacf272020-10-22 14:08:27 -0700113
Dominik Laskowskie21dbed2020-12-04 20:51:43 -0800114 template <typename T, std::size_t N, std::size_t M>
115 friend bool operator>(const Array<T, N>& lhs, const Array<T, M>& rhs) {
116 return rhs < lhs;
117 }
Dominik Laskowski0bacf272020-10-22 14:08:27 -0700118
Dominik Laskowskie21dbed2020-12-04 20:51:43 -0800119 template <typename T, std::size_t N, std::size_t M>
120 friend bool operator!=(const Array<T, N>& lhs, const Array<T, M>& rhs) {
121 return !(lhs == rhs);
122 }
Dominik Laskowski0bacf272020-10-22 14:08:27 -0700123
Dominik Laskowskie21dbed2020-12-04 20:51:43 -0800124 template <typename T, std::size_t N, std::size_t M>
125 friend bool operator>=(const Array<T, N>& lhs, const Array<T, M>& rhs) {
126 return !(lhs < rhs);
127 }
Dominik Laskowski0bacf272020-10-22 14:08:27 -0700128
Dominik Laskowskie21dbed2020-12-04 20:51:43 -0800129 template <typename T, std::size_t N, std::size_t M>
130 friend bool operator<=(const Array<T, N>& lhs, const Array<T, M>& rhs) {
131 return !(lhs > rhs);
132 }
Dominik Laskowski0bacf272020-10-22 14:08:27 -0700133};
134
Dominik Laskowskie21dbed2020-12-04 20:51:43 -0800135} // namespace android::ftl