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/*
* Copyright (C) 2015-2016 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. ``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
* 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<class Container>
class IndexedContainerIterator {
WTF_MAKE_FAST_ALLOCATED;
public:
IndexedContainerIterator()
: m_container(nullptr)
, m_index(0)
{
}
IndexedContainerIterator(const Container& container, unsigned index)
: m_container(&container)
, m_index(findNext(index))
{
}
auto operator*() -> typename std::invoke_result<decltype(&Container::at), const Container, unsigned>::type
{
return m_container->at(m_index);
}
IndexedContainerIterator& operator++()
{
m_index = findNext(m_index + 1);
return *this;
}
bool operator==(const IndexedContainerIterator& other) const
{
ASSERT(m_container == other.m_container);
return m_index == other.m_index;
}
private:
unsigned findNext(unsigned index)
{
while (index < m_container->size() && !m_container->at(index))
index++;
return index;
}
const Container* m_container;
unsigned m_index;
};
} // namespace WTF
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