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- // Copyright (c) 2011 The Chromium Authors. All rights reserved.
- // Use of this source code is governed by a BSD-style license that can be
- // found in the LICENSE file.
- #ifndef BASE_MEMORY_RAW_SCOPED_REFPTR_MISMATCH_CHECKER_H_
- #define BASE_MEMORY_RAW_SCOPED_REFPTR_MISMATCH_CHECKER_H_
- #include <type_traits>
- #include "base/memory/raw_ptr.h"
- #include "base/memory/raw_ref.h"
- #include "base/template_util.h"
- // It is dangerous to post a task with a T* argument where T is a subtype of
- // RefCounted(Base|ThreadSafeBase), since by the time the parameter is used, the
- // object may already have been deleted since it was not held with a
- // scoped_refptr. Example: http://crbug.com/27191
- // The following set of traits are designed to generate a compile error
- // whenever this antipattern is attempted.
- namespace base {
- // This is a base internal implementation file used by task.h and callback.h.
- // Not for public consumption, so we wrap it in namespace internal.
- namespace internal {
- template <typename T, typename = void>
- struct IsRefCountedType : std::false_type {};
- template <typename T>
- struct IsRefCountedType<T,
- std::void_t<decltype(std::declval<T*>()->AddRef()),
- decltype(std::declval<T*>()->Release())>>
- : std::true_type {};
- // Human readable translation: you needed to be a scoped_refptr if you are a raw
- // pointer type and are convertible to a RefCounted(Base|ThreadSafeBase) type.
- template <typename T>
- struct NeedsScopedRefptrButGetsRawPtr
- : std::disjunction<
- // TODO(danakj): Should ban native references and
- // std::reference_wrapper here too.
- std::conjunction<base::IsRawRef<T>,
- IsRefCountedType<base::RemoveRawRefT<T>>>,
- std::conjunction<base::IsPointer<T>,
- IsRefCountedType<base::RemovePointerT<T>>>> {
- static_assert(!std::is_reference<T>::value,
- "NeedsScopedRefptrButGetsRawPtr requires non-reference type.");
- };
- } // namespace internal
- } // namespace base
- #endif // BASE_MEMORY_RAW_SCOPED_REFPTR_MISMATCH_CHECKER_H_
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