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/*
* Copyright (C) 2013 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <type_traits>
namespace WTF {
template<typename Predicate, typename Iterator>
class FilterIterator {
WTF_MAKE_FAST_ALLOCATED;
public:
FilterIterator(Predicate pred, Iterator begin, Iterator end)
: m_pred(WTFMove(pred))
, m_iter(WTFMove(begin))
, m_end(WTFMove(end))
{
while (m_iter != m_end && !m_pred(*m_iter))
++m_iter;
}
FilterIterator& operator++()
{
while (m_iter != m_end) {
++m_iter;
if (m_iter == m_end || m_pred(*m_iter))
break;
}
return *this;
}
const typename std::remove_const<decltype(*std::declval<Iterator>())>::type operator*() const
{
ASSERT(m_iter != m_end);
ASSERT(m_pred(*m_iter));
return *m_iter;
}
inline bool operator==(const FilterIterator& other) const { return m_iter == other.m_iter; }
inline bool operator!=(const FilterIterator& other) const { return m_iter != other.m_iter; }
private:
const Predicate m_pred;
Iterator m_iter;
Iterator m_end;
};
template<typename Predicate, typename Iterator>
inline FilterIterator<Predicate, Iterator> makeFilterIterator(Predicate&& pred, Iterator&& begin, Iterator&& end)
{
return FilterIterator<Predicate, Iterator>(std::forward<Predicate>(pred), std::forward<Iterator>(begin), std::forward<Iterator>(end));
}
template<typename Transform, typename Iterator>
class TransformIterator {
WTF_MAKE_FAST_ALLOCATED;
public:
TransformIterator(Transform&& transform, Iterator&& iter)
: m_transform(WTFMove(transform))
, m_iter(WTFMove(iter))
{
}
TransformIterator& operator++()
{
++m_iter;
return *this;
}
const typename std::remove_const<decltype(std::declval<Transform>()(*std::declval<Iterator>()))>::type operator*() const
{
return m_transform(*m_iter);
}
inline bool operator==(const TransformIterator& other) const { return m_iter == other.m_iter; }
inline bool operator!=(const TransformIterator& other) const { return m_iter != other.m_iter; }
private:
const Transform m_transform;
Iterator m_iter;
};
template<typename Transform, typename Iterator>
inline TransformIterator<Transform, Iterator> makeTransformIterator(Transform&& transform, Iterator&& iter)
{
return TransformIterator<Transform, Iterator>(WTFMove(transform), WTFMove(iter));
}
} // namespace WTF