1//===-- A self contained equivalent of std::array ---------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef LLVM_LIBC_SRC___SUPPORT_CPP_ARRAY_H
10#define LLVM_LIBC_SRC___SUPPORT_CPP_ARRAY_H
11
12#include "src/__support/CPP/iterator.h" // reverse_iterator
13#include "src/__support/macros/attributes.h"
14#include "src/__support/macros/config.h"
15#include <stddef.h> // For size_t.
16
17namespace LIBC_NAMESPACE_DECL {
18namespace cpp {
19
20template <class T, size_t N> struct array {
21 static_assert(N != 0,
22 "Cannot create a LIBC_NAMESPACE::cpp::array of size 0.");
23
24 T Data[N];
25 using value_type = T;
26 using iterator = T *;
27 using const_iterator = const T *;
28 using reverse_iterator = cpp::reverse_iterator<iterator>;
29 using const_reverse_iterator = cpp::reverse_iterator<const_iterator>;
30
31 LIBC_INLINE constexpr T *data() { return Data; }
32 LIBC_INLINE constexpr const T *data() const { return Data; }
33
34 LIBC_INLINE constexpr T &front() { return Data[0]; }
35 LIBC_INLINE constexpr const T &front() const { return Data[0]; }
36
37 LIBC_INLINE constexpr T &back() { return Data[N - 1]; }
38 LIBC_INLINE constexpr const T &back() const { return Data[N - 1]; }
39
40 LIBC_INLINE constexpr T &operator[](size_t Index) { return Data[Index]; }
41
42 LIBC_INLINE constexpr const T &operator[](size_t Index) const {
43 return Data[Index];
44 }
45
46 LIBC_INLINE constexpr size_t size() const { return N; }
47
48 LIBC_INLINE constexpr bool empty() const { return N == 0; }
49
50 LIBC_INLINE constexpr iterator begin() { return Data; }
51 LIBC_INLINE constexpr const_iterator begin() const { return Data; }
52 LIBC_INLINE constexpr const_iterator cbegin() const { return begin(); }
53
54 LIBC_INLINE constexpr iterator end() { return Data + N; }
55 LIBC_INLINE constexpr const_iterator end() const { return Data + N; }
56 LIBC_INLINE constexpr const_iterator cend() const { return end(); }
57
58 LIBC_INLINE constexpr reverse_iterator rbegin() {
59 return reverse_iterator{end()};
60 }
61 LIBC_INLINE constexpr const_reverse_iterator rbegin() const {
62 return const_reverse_iterator{end()};
63 }
64 LIBC_INLINE constexpr const_reverse_iterator crbegin() const {
65 return rbegin();
66 }
67
68 LIBC_INLINE constexpr reverse_iterator rend() {
69 return reverse_iterator{begin()};
70 }
71 LIBC_INLINE constexpr const_reverse_iterator rend() const {
72 return const_reverse_iterator{begin()};
73 }
74 LIBC_INLINE constexpr const_reverse_iterator crend() const { return rend(); }
75};
76
77} // namespace cpp
78} // namespace LIBC_NAMESPACE_DECL
79
80#endif // LLVM_LIBC_SRC___SUPPORT_CPP_ARRAY_H
81