string/detail/trim.hpp

0001 //  Boost string_algo library trim.hpp header file  ---------------------------//
0002
0003 //  Copyright Pavol Droba 2002-2003.
0004 //
0005 // Distributed under the Boost Software License, Version 1.0.
0006 //    (See accompanying file LICENSE_1_0.txt or copy at
0007 //          http://www.boost.org/LICENSE_1_0.txt)
0008
0009 //  See http://www.boost.org/ for updates, documentation, and revision history.
0010
0011 #ifndef BOOST_STRING_TRIM_DETAIL_HPP
0012 #define BOOST_STRING_TRIM_DETAIL_HPP
0013
0014 #include <boost/algorithm/string/config.hpp>
0015 #include <iterator>
0016
0017 namespace boost {
0018     namespace algorithm {
0019         namespace detail {
0020
0021 //  trim iterator helper -----------------------------------------------//
0022
0023             template< typename ForwardIteratorT, typename PredicateT >
0024             inline ForwardIteratorT trim_end_iter_select(
0025                 ForwardIteratorT InBegin,
0026                 ForwardIteratorT InEnd,
0027                 PredicateT IsSpace,
0028                 std::forward_iterator_tag )
0029             {
0030                 ForwardIteratorT TrimIt=InBegin;
0031
0032                 for( ForwardIteratorT It=InBegin; It!=InEnd; ++It )
0033                 {
0034                     if ( !IsSpace(*It) )
0035                     {
0036                         TrimIt=It;
0037                         ++TrimIt;
0038                     }
0039                 }
0040
0041                 return TrimIt;
0042             }
0043
0044             template< typename ForwardIteratorT, typename PredicateT >
0045             inline ForwardIteratorT trim_end_iter_select(
0046                 ForwardIteratorT InBegin,
0047                 ForwardIteratorT InEnd,
0048                 PredicateT IsSpace,
0049                 std::bidirectional_iterator_tag )
0050             {
0051                 for( ForwardIteratorT It=InEnd; It!=InBegin;  )
0052                 {
0053                     if ( !IsSpace(*(--It)) )
0054                         return ++It;
0055                 }
0056
0057                 return InBegin;
0058             }
0059    // Search for first non matching character from the beginning of the sequence
0060             template< typename ForwardIteratorT, typename PredicateT >
0061             inline ForwardIteratorT trim_begin(
0062                 ForwardIteratorT InBegin,
0063                 ForwardIteratorT InEnd,
0064                 PredicateT IsSpace )
0065             {
0066                 ForwardIteratorT It=InBegin;
0067                 for(; It!=InEnd; ++It )
0068                 {
0069                     if (!IsSpace(*It))
0070                         return It;
0071                 }
0072
0073                 return It;
0074             }
0075
0076             // Search for first non matching character from the end of the sequence
0077             template< typename ForwardIteratorT, typename PredicateT >
0078             inline ForwardIteratorT trim_end(
0079                 ForwardIteratorT InBegin,
0080                 ForwardIteratorT InEnd,
0081                 PredicateT IsSpace )
0082             {
0083                 typedef BOOST_STRING_TYPENAME
0084                     std::iterator_traits<ForwardIteratorT>::iterator_category category;
0085
0086                 return ::boost::algorithm::detail::trim_end_iter_select( InBegin, InEnd, IsSpace, category() );
0087             }
0088
0089
0090         } // namespace detail
0091     } // namespace algorithm
0092 } // namespace boost
0093
0094
0095 #endif  // BOOST_STRING_TRIM_DETAIL_HPP