knnGraphRangeIterator.h

/*
 This Source Code Form is subject to the terms of the Mozilla Public
 License, v. 2.0. If a copy of the MPL was not distributed with this
 file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
 
#pragma once
 
#include <iterator>
#include <cstddef>
 
namespace Ponca {
 
template <typename Traits>
class KnnGraphRangeQuery;
 
template <typename Traits>
class KnnGraphRangeIterator
{
protected:
    friend class KnnGraphRangeQuery<Traits>;
    using Index  = typename Traits::IndexType;
public:
    // Tagged as an input iterator, because the increment logic is shared between iterators of the same queries.
    // Which makes the iterator not valid when duplicated (through postfix increment for example).
    using iterator_category = PONCA_MULTIARCH_CU_STD_NAMESPACE(input_iterator_tag);
    using difference_type   = std::ptrdiff_t;
    using value_type = Index;
    using pointer    = Index*;
    using reference  = const Index&;
 
    inline KnnGraphRangeIterator(KnnGraphRangeQuery<Traits>* query, Index index = Index(-1)) : m_query(query), m_index(index) {}
 
public:
    bool operator != (const KnnGraphRangeIterator& other) const{
        return m_index != other.m_index;
    }
 
    bool operator == (const KnnGraphRangeIterator& other) const {
        return m_index == other.m_index;
    }
 
    inline KnnGraphRangeIterator& operator ++ (){
        m_query->advance(*this);
        return *this;
    }
 
    inline void operator++(value_type) { ++*this; }
 
    inline reference operator *() const {
        return const_cast<reference>(m_index);
    }
 
protected:
    KnnGraphRangeQuery<Traits>* m_query {nullptr};
    value_type m_index {-1};
};
 
} // namespace Ponca