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Diffstat (limited to 'boost/archive/iterators/head_iterator.hpp')
-rw-r--r-- | boost/archive/iterators/head_iterator.hpp | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/boost/archive/iterators/head_iterator.hpp b/boost/archive/iterators/head_iterator.hpp new file mode 100644 index 0000000000..7d39a35da0 --- /dev/null +++ b/boost/archive/iterators/head_iterator.hpp @@ -0,0 +1,80 @@ +#ifndef BOOST_ARCHIVE_ITERATORS_HEAD_ITERATOR_HPP +#define BOOST_ARCHIVE_ITERATORS_HEAD_ITERATOR_HPP + +// MS compatible compilers support #pragma once +#if defined(_MSC_VER) && (_MSC_VER >= 1020) +# pragma once +#endif + +/////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8 +// head_iterator.hpp + +// (C) Copyright 2002 Robert Ramey - http://www.rrsd.com . +// Use, modification and distribution is subject to 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. + +#include <boost/iterator/iterator_adaptor.hpp> +#include <boost/iterator/iterator_traits.hpp> + +namespace boost { +namespace archive { +namespace iterators { + +template<class Predicate, class Base> +class head_iterator + : public boost::iterator_adaptor< + head_iterator<Predicate, Base>, + Base, + use_default, + single_pass_traversal_tag + > +{ +private: + friend class iterator_core_access; + typedef boost::iterator_adaptor< + head_iterator<Predicate, Base>, + Base, + use_default, + single_pass_traversal_tag + > super_t; + + typedef head_iterator<Predicate, Base> this_t; + typedef BOOST_DEDUCED_TYPENAME super_t::value_type value_type; + typedef BOOST_DEDUCED_TYPENAME super_t::reference reference_type; + + reference_type dereference_impl(){ + if(! m_end){ + while(! m_predicate(* this->base_reference())) + ++ this->base_reference(); + m_end = true; + } + return * this->base_reference(); + } + + reference_type dereference() const { + return const_cast<this_t *>(this)->dereference_impl(); + } + + void increment(){ + ++base_reference(); + } + Predicate m_predicate; + bool m_end; +public: + template<class T> + head_iterator(Predicate f, T start) : + super_t(Base(start)), + m_predicate(f), + m_end(false) + {} + +}; + +} // namespace iterators +} // namespace archive +} // namespace boost + +#endif // BOOST_ARCHIVE_ITERATORS_HEAD_ITERATOR_HPP |