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Diffstat (limited to 'boost/algorithm/string/join.hpp')
-rw-r--r-- | boost/algorithm/string/join.hpp | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/boost/algorithm/string/join.hpp b/boost/algorithm/string/join.hpp new file mode 100644 index 000000000..b871eb44f --- /dev/null +++ b/boost/algorithm/string/join.hpp @@ -0,0 +1,145 @@ +// Boost string_algo library join.hpp header file ---------------------------// + +// Copyright Pavol Droba 2002-2006. +// +// 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_JOIN_HPP +#define BOOST_STRING_JOIN_HPP + +#include <boost/algorithm/string/config.hpp> +#include <boost/algorithm/string/detail/sequence.hpp> +#include <boost/range/value_type.hpp> +#include <boost/range/as_literal.hpp> + +/*! \file + Defines join algorithm. + + Join algorithm is a counterpart to split algorithms. + It joins strings from a 'list' by adding user defined separator. + Additionally there is a version that allows simple filtering + by providing a predicate. +*/ + +namespace boost { + namespace algorithm { + +// join --------------------------------------------------------------// + + //! Join algorithm + /*! + This algorithm joins all strings in a 'list' into one long string. + Segments are concatenated by given separator. + + \param Input A container that holds the input strings. It must be a container-of-containers. + \param Separator A string that will separate the joined segments. + \return Concatenated string. + + \note This function provides the strong exception-safety guarantee + */ + template< typename SequenceSequenceT, typename Range1T> + inline typename range_value<SequenceSequenceT>::type + join( + const SequenceSequenceT& Input, + const Range1T& Separator) + { + // Define working types + typedef typename range_value<SequenceSequenceT>::type ResultT; + typedef typename range_const_iterator<SequenceSequenceT>::type InputIteratorT; + + // Parse input + InputIteratorT itBegin=::boost::begin(Input); + InputIteratorT itEnd=::boost::end(Input); + + // Construct container to hold the result + ResultT Result; + + // Append first element + if(itBegin!=itEnd) + { + detail::insert(Result, ::boost::end(Result), *itBegin); + ++itBegin; + } + + for(;itBegin!=itEnd; ++itBegin) + { + // Add separator + detail::insert(Result, ::boost::end(Result), ::boost::as_literal(Separator)); + // Add element + detail::insert(Result, ::boost::end(Result), *itBegin); + } + + return Result; + } + +// join_if ----------------------------------------------------------// + + //! Conditional join algorithm + /*! + This algorithm joins all strings in a 'list' into one long string. + Segments are concatenated by given separator. Only segments that + satisfy the predicate will be added to the result. + + \param Input A container that holds the input strings. It must be a container-of-containers. + \param Separator A string that will separate the joined segments. + \param Pred A segment selection predicate + \return Concatenated string. + + \note This function provides the strong exception-safety guarantee + */ + template< typename SequenceSequenceT, typename Range1T, typename PredicateT> + inline typename range_value<SequenceSequenceT>::type + join_if( + const SequenceSequenceT& Input, + const Range1T& Separator, + PredicateT Pred) + { + // Define working types + typedef typename range_value<SequenceSequenceT>::type ResultT; + typedef typename range_const_iterator<SequenceSequenceT>::type InputIteratorT; + + // Parse input + InputIteratorT itBegin=::boost::begin(Input); + InputIteratorT itEnd=::boost::end(Input); + + // Construct container to hold the result + ResultT Result; + + // Roll to the first element that will be added + while(itBegin!=itEnd && !Pred(*itBegin)) ++itBegin; + // Add this element + if(itBegin!=itEnd) + { + detail::insert(Result, ::boost::end(Result), *itBegin); + ++itBegin; + } + + for(;itBegin!=itEnd; ++itBegin) + { + if(Pred(*itBegin)) + { + // Add separator + detail::insert(Result, ::boost::end(Result), ::boost::as_literal(Separator)); + // Add element + detail::insert(Result, ::boost::end(Result), *itBegin); + } + } + + return Result; + } + + } // namespace algorithm + + // pull names to the boost namespace + using algorithm::join; + using algorithm::join_if; + +} // namespace boost + + +#endif // BOOST_STRING_JOIN_HPP + |