openspades/Sources/Core/Iterator.h
2019-07-14 18:29:50 +09:00

54 lines
1.5 KiB
C++

/*
Copyright (c) 2019 yvt
This file is part of OpenSpades.
OpenSpades is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
OpenSpades is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with OpenSpades. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <Core/Debug.h>
#include <Core/RefCountedObject.h>
namespace spades {
/**
* Represents an iterator object.
*
* At the initial state, it does not point any element. `MoveNext` must be
* called first to move the iterator to the first element.
*/
template <class T> class Iterator : public RefCountedObject {
public:
/**
* Get the current item.
*/
virtual T GetCurrent() = 0;
/**
* Advance the iterator.
*
* @return `true` if the iterator was successfully advanced to the next
* element. `false` if it reached the end of the sequence.
*/
virtual bool MoveNext() = 0;
};
/** Represents an iterator that produces no elements. */
template <class T> class EmptyIterator final : public Iterator<T> {
public:
T GetCurrent() override { SPUnreachable(); }
bool MoveNext() override { return false; }
};
} // namespace spades