1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/dom/bindings/OwningNonNull.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,87 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* vim: set ts=8 sts=2 et sw=2 tw=80: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +/* A class for non-null strong pointers to reference-counted objects. */
1.11 +
1.12 +#ifndef mozilla_dom_OwningNonNull_h
1.13 +#define mozilla_dom_OwningNonNull_h
1.14 +
1.15 +#include "nsAutoPtr.h"
1.16 +
1.17 +namespace mozilla {
1.18 +namespace dom {
1.19 +
1.20 +template<class T>
1.21 +class OwningNonNull
1.22 +{
1.23 +public:
1.24 + OwningNonNull()
1.25 +#ifdef DEBUG
1.26 + : mInited(false)
1.27 +#endif
1.28 + {}
1.29 +
1.30 + operator T&()
1.31 + {
1.32 + MOZ_ASSERT(mInited);
1.33 + MOZ_ASSERT(mPtr, "OwningNonNull<T> was set to null");
1.34 + return *mPtr;
1.35 + }
1.36 +
1.37 + operator T*()
1.38 + {
1.39 + MOZ_ASSERT(mInited);
1.40 + MOZ_ASSERT(mPtr, "OwningNonNull<T> was set to null");
1.41 + return mPtr;
1.42 + }
1.43 +
1.44 + void operator=(T* aValue)
1.45 + {
1.46 + init(aValue);
1.47 + }
1.48 +
1.49 + void operator=(const already_AddRefed<T>& aValue)
1.50 + {
1.51 + init(aValue);
1.52 + }
1.53 +
1.54 + already_AddRefed<T> forget()
1.55 + {
1.56 +#ifdef DEBUG
1.57 + mInited = false;
1.58 +#endif
1.59 + return mPtr.forget();
1.60 + }
1.61 +
1.62 + // Make us work with smart pointer helpers that expect a get().
1.63 + T* get() const
1.64 + {
1.65 + MOZ_ASSERT(mInited);
1.66 + MOZ_ASSERT(mPtr);
1.67 + return mPtr;
1.68 + }
1.69 +
1.70 +protected:
1.71 + template<typename U>
1.72 + void init(U aValue)
1.73 + {
1.74 + mPtr = aValue;
1.75 + MOZ_ASSERT(mPtr);
1.76 +#ifdef DEBUG
1.77 + mInited = true;
1.78 +#endif
1.79 + }
1.80 +
1.81 + nsRefPtr<T> mPtr;
1.82 +#ifdef DEBUG
1.83 + bool mInited;
1.84 +#endif
1.85 +};
1.86 +
1.87 +} // namespace dom
1.88 +} // namespace mozilla
1.89 +
1.90 +#endif // mozilla_dom_OwningNonNull_h
