iteratorUtils.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 "../defines.h"
#include <algorithm>
 
namespace Ponca::internal
{
    template <class ForwardIt, class T = typename std::iterator_traits<ForwardIt>::value_type>
    PONCA_MULTIARCH void fill(ForwardIt first, ForwardIt last, const T& value)
    {
#ifdef __CUDA_ARCH__
        for (; first != last; ++first)
            *first = value;
#else
        std::fill(first, last, value);
#endif
    }
 
    template <class ForwardIt, class T = typename std::iterator_traits<ForwardIt>::value_type, class Compare>
    PONCA_MULTIARCH ForwardIt upperBound(ForwardIt first, ForwardIt last, const T& value, Compare comp)
    {
#ifdef __CUDA_ARCH__
        ForwardIt it;
        typename std::iterator_traits<ForwardIt>::difference_type count, step;
        count = last - first;
 
        while (count > 0)
        {
            it   = first;
            step = count / 2;
            it += step;
 
            if (!comp(value, *it))
            {
                first = ++it;
                count -= step + 1;
            }
            else
                count = step;
        }
 
        return first;
#else
        return std::upper_bound(first, last, value, comp);
#endif
    }
 
    template <class BidirIt1, class BidirIt2>
    PONCA_MULTIARCH BidirIt2 copyBackward(BidirIt1 first, BidirIt1 last, BidirIt2 d_last)
    {
#ifdef __CUDA_ARCH__
        while (first != last)
            *(--d_last) = *(--last);
        return d_last;
#else
        return std::copy_backward(first, last, d_last);
#endif
    }
} // namespace Ponca::internal