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- // Copyright (c) 2013 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_WIN_SCOPED_PROPVARIANT_H_
- #define BASE_WIN_SCOPED_PROPVARIANT_H_
- #include <propidl.h>
- #include "base/check_op.h"
- namespace base {
- namespace win {
- // A PROPVARIANT that is automatically initialized and cleared upon respective
- // construction and destruction of this class.
- class ScopedPropVariant {
- public:
- ScopedPropVariant() { PropVariantInit(&pv_); }
- ScopedPropVariant(const ScopedPropVariant&) = delete;
- ScopedPropVariant& operator=(const ScopedPropVariant&) = delete;
- ~ScopedPropVariant() { Reset(); }
- // Returns a pointer to the underlying PROPVARIANT for use as an out param in
- // a function call.
- PROPVARIANT* Receive() {
- DCHECK_EQ(pv_.vt, VT_EMPTY);
- return &pv_;
- }
- // Clears the instance to prepare it for re-use (e.g., via Receive).
- void Reset() {
- if (pv_.vt != VT_EMPTY) {
- HRESULT result = PropVariantClear(&pv_);
- DCHECK_EQ(result, S_OK);
- }
- }
- const PROPVARIANT& get() const { return pv_; }
- const PROPVARIANT* ptr() const { return &pv_; }
- private:
- PROPVARIANT pv_;
- // Comparison operators for ScopedPropVariant are not supported at this point.
- bool operator==(const ScopedPropVariant&) const;
- bool operator!=(const ScopedPropVariant&) const;
- };
- } // namespace win
- } // namespace base
- #endif // BASE_WIN_SCOPED_PROPVARIANT_H_
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