mfbt/Array.h
author Bryce Van Dyk <bvandyk@mozilla.com>
Mon, 27 Aug 2018 16:25:54 +0000
changeset 488616 259675bd67f96acf1ae0f2ed6115de4331a94d32
parent 475188 bb85c5ee5afc151be0d07ecc48318dc69cfef446
child 502575 79148f9b36487274b734e30b48a18608e250cc99
permissions -rw-r--r--
Bug 1486502 - Add widevine CDM headers to third party paths, clang-format ignore. r=sylvestre We wish to keep the widevine headers in the same formatting as upstream to ease comparison and as we do not modify these files. This patch adds the existing headers, as well as another we anticipate pulling down for our next bump (content_decryption_module_proxy.h) to the ignored paths. These files are ignored individually rather than the whole directory they're in, as we also have Mozilla code in that dir. Differential Revision: https://phabricator.services.mozilla.com/D4347

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/* A compile-time constant-length array with bounds-checking assertions. */

#ifndef mozilla_Array_h
#define mozilla_Array_h

#include "mozilla/Assertions.h"
#include "mozilla/Attributes.h"
#include "mozilla/Move.h"
#include "mozilla/ReverseIterator.h"

#include <stddef.h>

namespace mozilla {

template<typename T, size_t Length>
class Array
{
  T mArr[Length];

public:
  Array() {}

  template <typename... Args>
  MOZ_IMPLICIT Array(Args&&... aArgs)
    : mArr{std::forward<Args>(aArgs)...}
  {
    static_assert(sizeof...(aArgs) == Length,
                  "The number of arguments should be equal to the template parameter Length");
  }

  T& operator[](size_t aIndex)
  {
    MOZ_ASSERT(aIndex < Length);
    return mArr[aIndex];
  }

  const T& operator[](size_t aIndex) const
  {
    MOZ_ASSERT(aIndex < Length);
    return mArr[aIndex];
  }

  bool operator==(const Array<T, Length>& aOther) const
  {
    for (size_t i = 0; i < Length; i++) {
      if (mArr[i] != aOther[i]) {
        return false;
      }
    }
    return true;
  }

  typedef T*                        iterator;
  typedef const T*                  const_iterator;
  typedef ReverseIterator<T*>       reverse_iterator;
  typedef ReverseIterator<const T*> const_reverse_iterator;

  // Methods for range-based for loops.
  iterator begin() { return mArr; }
  const_iterator begin() const { return mArr; }
  const_iterator cbegin() const { return begin(); }
  iterator end() { return mArr + Length; }
  const_iterator end() const { return mArr + Length; }
  const_iterator cend() const { return end(); }

  // Methods for reverse iterating.
  reverse_iterator rbegin() { return reverse_iterator(end()); }
  const_reverse_iterator rbegin() const { return const_reverse_iterator(end()); }
  const_reverse_iterator crbegin() const { return rbegin(); }
  reverse_iterator rend() { return reverse_iterator(begin()); }
  const_reverse_iterator rend() const { return const_reverse_iterator(begin()); }
  const_reverse_iterator crend() const { return rend(); }
};

template<typename T>
class Array<T, 0>
{
public:
  T& operator[](size_t aIndex)
  {
    MOZ_CRASH("indexing into zero-length array");
  }

  const T& operator[](size_t aIndex) const
  {
    MOZ_CRASH("indexing into zero-length array");
  }
};

}  /* namespace mozilla */

#endif /* mozilla_Array_h */