81 lines
1.2 KiB
C++
81 lines
1.2 KiB
C++
/*
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* \brief Pointer that can be dereferenced only when valid
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* \author Martin Stein
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* \date 2016-08-24
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*/
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/*
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* Copyright (C) 2016-2017 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU Affero General Public License version 3.
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*/
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#ifndef _POINTER_H_
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#define _POINTER_H_
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/* Genode includes */
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#include <base/exception.h>
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namespace Local {
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template <typename> class Pointer;
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template <typename> class Const_pointer;
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}
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template <typename T>
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class Local::Pointer
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{
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private:
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T *_obj;
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public:
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struct Invalid : Genode::Exception { };
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Pointer() : _obj(nullptr) { }
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Pointer(T &obj) : _obj(&obj) { }
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T &operator () () const
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{
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if (_obj == nullptr)
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throw Invalid();
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return *_obj;
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}
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bool valid() const { return _obj != nullptr; }
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};
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template <typename T>
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class Local::Const_pointer
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{
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private:
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T const *_obj;
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public:
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struct Invalid : Genode::Exception { };
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Const_pointer() : _obj(nullptr) { }
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Const_pointer(T const &obj) : _obj(&obj) { }
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T const &operator () () const
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{
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if (_obj == nullptr)
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throw Invalid();
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return *_obj;
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}
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bool valid() const { return _obj != nullptr; }
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};
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#endif /* _POINTER_H_ */
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