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