libc/src/__support/CPP/array.h

   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/macros/attributes.h"
  13 #include <stddef.h> // For size_t.
  14
  15 namespace LIBC_NAMESPACE {
  16 namespace cpp {
  17
  18 template <class T, size_t N> struct array {
  19   static_assert(N != 0,
  20                 "Cannot create a LIBC_NAMESPACE::cpp::array of size 0.");
  21
  22   T Data[N];
  23   using value_type = T;
  24   using iterator = T *;
  25   using const_iterator = const T *;
  26
  27   LIBC_INLINE constexpr T *data() { return Data; }
  28   LIBC_INLINE constexpr const T *data() const { return Data; }
  29
  30   LIBC_INLINE constexpr T &front() { return Data[0]; }
  31   LIBC_INLINE constexpr T &front() const { return Data[0]; }
  32
  33   LIBC_INLINE constexpr T &back() { return Data[N - 1]; }
  34   LIBC_INLINE constexpr T &back() const { return Data[N - 1]; }
  35
  36   LIBC_INLINE constexpr T &operator[](size_t Index) { return Data[Index]; }
  37
  38   LIBC_INLINE constexpr const T &operator[](size_t Index) const {
  39     return Data[Index];
  40   }
  41
  42   LIBC_INLINE constexpr size_t size() const { return N; }
  43
  44   LIBC_INLINE constexpr bool empty() const { return N == 0; }
  45
  46   LIBC_INLINE constexpr iterator begin() { return Data; }
  47   LIBC_INLINE constexpr const_iterator begin() const { return Data; }
  48
  49   LIBC_INLINE constexpr iterator end() { return Data + N; }
  50   LIBC_INLINE const_iterator end() const { return Data + N; }
  51 };
  52
  53 } // namespace cpp
  54 } // namespace LIBC_NAMESPACE
  55
  56 #endif // LLVM_LIBC_SRC___SUPPORT_CPP_ARRAY_H