ext-boost/boost/algorithm/string/detail/replace_storage.hpp
2019-08-24 15:39:04 +02:00

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// Boost string_algo library replace_storage.hpp header file ---------------------------//
// Copyright Pavol Droba 2002-2003.
//
// 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/ for updates, documentation, and revision history.
#ifndef BOOST_STRING_REPLACE_STORAGE_DETAIL_HPP
#define BOOST_STRING_REPLACE_STORAGE_DETAIL_HPP
#include <boost/algorithm/string/config.hpp>
#include <algorithm>
#include <boost/mpl/bool.hpp>
#include <boost/algorithm/string/sequence_traits.hpp>
#include <boost/algorithm/string/detail/sequence.hpp>
namespace boost {
namespace algorithm {
namespace detail {
// storage handling routines -----------------------------------------------//
template< typename StorageT, typename OutputIteratorT >
inline OutputIteratorT move_from_storage(
StorageT& Storage,
OutputIteratorT DestBegin,
OutputIteratorT DestEnd )
{
OutputIteratorT OutputIt=DestBegin;
while( !Storage.empty() && OutputIt!=DestEnd )
{
*OutputIt=Storage.front();
Storage.pop_front();
++OutputIt;
}
return OutputIt;
}
template< typename StorageT, typename WhatT >
inline void copy_to_storage(
StorageT& Storage,
const WhatT& What )
{
Storage.insert( Storage.end(), ::boost::begin(What), ::boost::end(What) );
}
// process segment routine -----------------------------------------------//
template< bool HasStableIterators >
struct process_segment_helper
{
// Optimized version of process_segment for generic sequence
template<
typename StorageT,
typename InputT,
typename ForwardIteratorT >
ForwardIteratorT operator()(
StorageT& Storage,
InputT& /*Input*/,
ForwardIteratorT InsertIt,
ForwardIteratorT SegmentBegin,
ForwardIteratorT SegmentEnd )
{
// Copy data from the storage until the beginning of the segment
ForwardIteratorT It=::boost::algorithm::detail::move_from_storage( Storage, InsertIt, SegmentBegin );
// 3 cases are possible :
// a) Storage is empty, It==SegmentBegin
// b) Storage is empty, It!=SegmentBegin
// c) Storage is not empty
if( Storage.empty() )
{
if( It==SegmentBegin )
{
// Case a) everything is grand, just return end of segment
return SegmentEnd;
}
else
{
// Case b) move the segment backwards
return std::copy( SegmentBegin, SegmentEnd, It );
}
}
else
{
// Case c) -> shift the segment to the left and keep the overlap in the storage
while( It!=SegmentEnd )
{
// Store value into storage
Storage.push_back( *It );
// Get the top from the storage and put it here
*It=Storage.front();
Storage.pop_front();
// Advance
++It;
}
return It;
}
}
};
template<>
struct process_segment_helper< true >
{
// Optimized version of process_segment for list-like sequence
template<
typename StorageT,
typename InputT,
typename ForwardIteratorT >
ForwardIteratorT operator()(
StorageT& Storage,
InputT& Input,
ForwardIteratorT InsertIt,
ForwardIteratorT SegmentBegin,
ForwardIteratorT SegmentEnd )
{
// Call replace to do the job
::boost::algorithm::detail::replace( Input, InsertIt, SegmentBegin, Storage );
// Empty the storage
Storage.clear();
// Iterators were not changed, simply return the end of segment
return SegmentEnd;
}
};
// Process one segment in the replace_all algorithm
template<
typename StorageT,
typename InputT,
typename ForwardIteratorT >
inline ForwardIteratorT process_segment(
StorageT& Storage,
InputT& Input,
ForwardIteratorT InsertIt,
ForwardIteratorT SegmentBegin,
ForwardIteratorT SegmentEnd )
{
return
process_segment_helper<
has_stable_iterators<InputT>::value>()(
Storage, Input, InsertIt, SegmentBegin, SegmentEnd );
}
} // namespace detail
} // namespace algorithm
} // namespace boost
#endif // BOOST_STRING_REPLACE_STORAGE_DETAIL_HPP