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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_WIN_ENUM_VARIANT_H_
#define BASE_WIN_ENUM_VARIANT_H_
#include <unknwn.h>
#include "base/memory/scoped_ptr.h"
#include "base/win/iunknown_impl.h"
namespace base {
namespace win {
// A simple implementation of IEnumVARIANT.
class BASE_EXPORT EnumVariant
: public IEnumVARIANT,
public IUnknownImpl {
public:
// The constructor allocates an array of size |count|. Then use
// ItemAt to set the value of each item in the array to initialize it.
explicit EnumVariant(unsigned long count);
// Returns a mutable pointer to the item at position |index|.
VARIANT* ItemAt(unsigned long index);
// IUnknown.
ULONG STDMETHODCALLTYPE AddRef() override;
ULONG STDMETHODCALLTYPE Release() override;
STDMETHODIMP QueryInterface(REFIID riid, void** ppv) override;
// IEnumVARIANT.
STDMETHODIMP Next(ULONG requested_count,
VARIANT* out_elements,
ULONG* out_elements_received) override;
STDMETHODIMP Skip(ULONG skip_count) override;
STDMETHODIMP Reset() override;
STDMETHODIMP Clone(IEnumVARIANT** out_cloned_object) override;
private:
~EnumVariant() override;
scoped_ptr<VARIANT[]> items_;
unsigned long count_;
unsigned long current_index_;
};
} // namespace win
} // namespace base
#endif // BASE_WIN_ENUM_VARIANT_H_