boost/compute/detail/is_contiguous_iterator.hpp
//---------------------------------------------------------------------------// // Copyright (c) 2013 Kyle Lutz <kyle.r.lutz@gmail.com> // // 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://boostorg.github.com/compute for more information. //---------------------------------------------------------------------------// #ifndef BOOST_COMPUTE_DETAIL_IS_CONTIGUOUS_ITERATOR_HPP #define BOOST_COMPUTE_DETAIL_IS_CONTIGUOUS_ITERATOR_HPP #include <vector> #include <valarray> #include <boost/config.hpp> #include <boost/type_traits.hpp> #include <boost/utility/enable_if.hpp> namespace boost { namespace compute { namespace detail { // default = false template<class Iterator, class Enable = void> struct _is_contiguous_iterator : public boost::false_type {}; // std::vector<T>::iterator = true template<class Iterator> struct _is_contiguous_iterator< Iterator, typename boost::enable_if< typename boost::is_same< Iterator, typename std::vector<typename Iterator::value_type>::iterator >::type >::type > : public boost::true_type {}; // std::vector<T>::const_iterator = true template<class Iterator> struct _is_contiguous_iterator< Iterator, typename boost::enable_if< typename boost::is_same< Iterator, typename std::vector<typename Iterator::value_type>::const_iterator >::type >::type > : public boost::true_type {}; // std::valarray<T>::iterator = true template<class Iterator> struct _is_contiguous_iterator< Iterator, typename boost::enable_if< typename boost::is_same< Iterator, typename std::valarray<typename Iterator::value_type>::iterator >::type >::type > : public boost::true_type {}; // std::valarray<T>::const_iterator = true template<class Iterator> struct _is_contiguous_iterator< Iterator, typename boost::enable_if< typename boost::is_same< Iterator, typename std::valarray<typename Iterator::value_type>::const_iterator >::type >::type > : public boost::true_type {}; // T* = true template<class Iterator> struct _is_contiguous_iterator< Iterator, typename boost::enable_if< boost::is_pointer<Iterator> >::type > : public boost::true_type {}; // the is_contiguous_iterator meta-function returns true if Iterator points // to a range of contiguous values. examples of contiguous iterators are // std::vector<>::iterator and float*. examples of non-contiguous iterators // are std::set<>::iterator and std::insert_iterator<>. // // the implementation consists of two phases. the first checks that value_type // for the iterator is not void. this must be done as for many containers void // is not a valid value_type (ex. std::vector<void>::iterator is not valid). // after ensuring a non-void value_type, the _is_contiguous_iterator function // is invoked. it has specializations retuning true for all (known) contiguous // iterators types and a default value of false. template<class Iterator, class Enable = void> struct is_contiguous_iterator : public _is_contiguous_iterator< typename boost::remove_cv<Iterator>::type > {}; // value_type of void = false template<class Iterator> struct is_contiguous_iterator< Iterator, typename boost::enable_if< typename boost::is_void< typename Iterator::value_type >::type >::type > : public boost::false_type {}; } // end detail namespace } // end compute namespace } // end boost namespace #endif // BOOST_COMPUTE_DETAIL_IS_CONTIGUOUS_ITERATOR_HPP