jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2020, the SerenityOS developers.
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#pragma once
8
9#include <AK/Iterator.h>
10#include <AK/Span.h>
11#include <AK/StdLibExtras.h>
12#include <AK/TypedTransfer.h>
13
14namespace AK {
15
16template<typename T, size_t Size>
17struct Array {
18 using ValueType = T;
19
20 // This is a static function because constructors mess up Array's POD-ness.
21 static Array from_span(Span<T> span)
22 {
23 Array array;
24 VERIFY(span.size() == Size);
25 TypedTransfer<T>::copy(array.data(), span.data(), Size);
26 return array;
27 }
28
29 [[nodiscard]] constexpr T const* data() const { return __data; }
30 [[nodiscard]] constexpr T* data() { return __data; }
31
32 [[nodiscard]] constexpr size_t size() const { return Size; }
33
34 [[nodiscard]] constexpr ReadonlySpan<T> span() const { return { __data, Size }; }
35 [[nodiscard]] constexpr Span<T> span() { return { __data, Size }; }
36
37 [[nodiscard]] constexpr T const& at(size_t index) const
38 {
39 VERIFY(index < size());
40 return __data[index];
41 }
42 [[nodiscard]] constexpr T& at(size_t index)
43 {
44 VERIFY(index < size());
45 return __data[index];
46 }
47
48 [[nodiscard]] constexpr T const& first() const { return at(0); }
49 [[nodiscard]] constexpr T& first() { return at(0); }
50
51 [[nodiscard]] constexpr T const& last() const
52 requires(Size > 0)
53 {
54 return at(Size - 1);
55 }
56 [[nodiscard]] constexpr T& last()
57 requires(Size > 0)
58 {
59 return at(Size - 1);
60 }
61
62 [[nodiscard]] constexpr bool is_empty() const { return size() == 0; }
63
64 [[nodiscard]] constexpr T const& operator[](size_t index) const { return at(index); }
65 [[nodiscard]] constexpr T& operator[](size_t index) { return at(index); }
66
67 template<typename T2, size_t Size2>
68 [[nodiscard]] constexpr bool operator==(Array<T2, Size2> const& other) const { return span() == other.span(); }
69
70 using ConstIterator = SimpleIterator<Array const, T const>;
71 using Iterator = SimpleIterator<Array, T>;
72
73 [[nodiscard]] constexpr ConstIterator begin() const { return ConstIterator::begin(*this); }
74 [[nodiscard]] constexpr Iterator begin() { return Iterator::begin(*this); }
75
76 [[nodiscard]] constexpr ConstIterator end() const { return ConstIterator::end(*this); }
77 [[nodiscard]] constexpr Iterator end() { return Iterator::end(*this); }
78
79 [[nodiscard]] constexpr operator ReadonlySpan<T>() const { return span(); }
80 [[nodiscard]] constexpr operator Span<T>() { return span(); }
81
82 constexpr size_t fill(T const& value)
83 {
84 for (size_t idx = 0; idx < Size; ++idx)
85 __data[idx] = value;
86
87 return Size;
88 }
89
90 [[nodiscard]] constexpr T max() const
91 requires(requires(T x, T y) { x < y; })
92 {
93 static_assert(Size > 0, "No values to max() over");
94
95 T value = __data[0];
96 for (size_t i = 1; i < Size; ++i)
97 value = AK::max(__data[i], value);
98 return value;
99 }
100
101 [[nodiscard]] constexpr T min() const
102 requires(requires(T x, T y) { x > y; })
103 {
104 static_assert(Size > 0, "No values to min() over");
105
106 T value = __data[0];
107 for (size_t i = 1; i < Size; ++i)
108 value = AK::min(__data[i], value);
109 return value;
110 }
111
112 T __data[Size];
113};
114
115template<typename T, typename... Types>
116Array(T, Types...) -> Array<T, sizeof...(Types) + 1>;
117
118namespace Detail {
119template<typename T, size_t... Is>
120constexpr auto integer_sequence_generate_array([[maybe_unused]] T const offset, IntegerSequence<T, Is...>) -> Array<T, sizeof...(Is)>
121{
122 return { { (offset + Is)... } };
123}
124}
125
126template<typename T, T N>
127constexpr static auto iota_array(T const offset = {})
128{
129 static_assert(N >= T {}, "Negative sizes not allowed in iota_array()");
130 return Detail::integer_sequence_generate_array<T>(offset, MakeIntegerSequence<T, N>());
131}
132
133}
134
135#if USING_AK_GLOBALLY
136using AK::Array;
137using AK::iota_array;
138#endif