//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2025-2026. Distributed under the Boost
// Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// See http://www.boost.org/libs/container for documentation.
//
//////////////////////////////////////////////////////////////////////////////
#ifndef BOOST_CONTAINER_EXPERIMENTAL_SEGMENTED_FILL_HPP
#define BOOST_CONTAINER_EXPERIMENTAL_SEGMENTED_FILL_HPP

#ifndef BOOST_CONFIG_HPP
#  include <boost/config.hpp>
#endif

#if defined(BOOST_HAS_PRAGMA_ONCE)
#  pragma once
#endif

#include <boost/container/detail/config_begin.hpp>
#include <boost/container/detail/workaround.hpp>
#include <boost/container/experimental/segmented_iterator_traits.hpp>
#include <boost/container/detail/iterator.hpp>
#include <boost/container/experimental/segmented_fill_n.hpp>

namespace boost {
namespace container {

template <class FwdIt, class Sent, class T>
void segmented_fill(FwdIt first, Sent last, const T& value);

namespace detail_algo {

template <class FwdIt, class Sent, class T, class Tag, class Cat>
BOOST_CONTAINER_FORCEINLINE typename algo_enable_if_c<
   !Tag::value || is_sentinel<Sent, FwdIt>::value>::type
segmented_fill_range(FwdIt first, Sent last, const T& value, Tag, Cat)
{
   BOOST_CONTAINER_SEGMENTED_UNROLL(4)
   for(; first != last; ++first)
      *first = value;
}

template <class SegIter, class T, class Cat>
void segmented_fill_range
   (SegIter first, SegIter last, const T& value, segmented_iterator_tag, Cat)
{
   typedef segmented_iterator_traits<SegIter>   traits;
   typedef typename traits::local_iterator      local_iterator;
   typedef typename traits::segment_iterator    segment_iterator;
   typedef typename segmented_iterator_traits<local_iterator>::is_segmented_iterator is_local_seg_t;
   typedef typename iterator_traits<local_iterator>::iterator_category local_cat_t;

   segment_iterator sfirst = traits::segment(first);
   segment_iterator slast  = traits::segment(last);

   if(sfirst == slast) {
      (segmented_fill_range)(traits::local(first), traits::local(last), value, is_local_seg_t(), local_cat_t());
   }
   else {
      (segmented_fill_range)(traits::local(first), traits::end(sfirst), value, is_local_seg_t(), local_cat_t());

      for(++sfirst; sfirst != slast; ++sfirst)
         (segmented_fill_range)(traits::begin(sfirst), traits::end(sfirst), value, is_local_seg_t(), local_cat_t());

      (segmented_fill_range)(traits::begin(sfirst), traits::local(last), value, is_local_seg_t(), local_cat_t());
   }
}

template <class FwdIt, class Sent, class T, class Cat>
BOOST_CONTAINER_FORCEINLINE
void segmented_fill_dispatch(FwdIt first, Sent last, const T& value, const Cat &)
{
   typedef segmented_iterator_traits<FwdIt> traits;
   (segmented_fill_range)(first, last, value, typename traits::is_segmented_iterator(), Cat());
}

} // namespace detail_algo

//! Assigns \c value to every element in [first, last).
//! When \c Iter is a segmented iterator, exploits segmentation
//! to reduce per-element overhead.
//! When \c Sent is the same type as \c FwdIt and the iterator
//! category is random access, derives to \c segmented_fill_n.
template <class FwdIt, class Sent, class T>
BOOST_CONTAINER_FORCEINLINE
void segmented_fill(FwdIt first, Sent last, const T& value)
{
   typedef segmented_iterator_traits<FwdIt> traits;
   (detail_algo::segmented_fill_range)( first, last, value
                                      , typename traits::is_segmented_iterator()
                                      , typename iterator_traits<FwdIt>::iterator_category());
}

} // namespace container
} // namespace boost

#include <boost/container/detail/config_end.hpp>

#endif // BOOST_CONTAINER_EXPERIMENTAL_SEGMENTED_FILL_HPP