mfbt/Array.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 /* A compile-time constant-length array with bounds-checking assertions. */
   8
   9 #ifndef mozilla_Array_h
  10 #define mozilla_Array_h
  11
  12 #include "mozilla/Assertions.h"
  13 #include "mozilla/Attributes.h"
  14
  15 #include <stddef.h>
  16
  17 namespace mozilla {
  18
  19 template<typename T, size_t Length>
  20 class Array
  21 {
  22   T mArr[Length];
  23
  24 public:
  25   T& operator[](size_t aIndex)
  26   {
  27     MOZ_ASSERT(aIndex < Length);
  28     return mArr[aIndex];
  29   }
  30
  31   const T& operator[](size_t aIndex) const
  32   {
  33     MOZ_ASSERT(aIndex < Length);
  34     return mArr[aIndex];
  35   }
  36 };
  37
  38 template<typename T>
  39 class Array<T, 0>
  40 {
  41 public:
  42   T& operator[](size_t aIndex)
  43   {
  44     MOZ_CRASH("indexing into zero-length array");
  45   }
  46
  47   const T& operator[](size_t aIndex) const
  48   {
  49     MOZ_CRASH("indexing into zero-length array");
  50   }
  51 };
  52
  53 }  /* namespace mozilla */
  54
  55 #endif /* mozilla_Array_h */