compute/algorithm/remove_if.hpp

0001 //---------------------------------------------------------------------------//
0002 // Copyright (c) 2013 Kyle Lutz <kyle.r.lutz@gmail.com>
0003 //
0004 // Distributed under the Boost Software License, Version 1.0
0005 // See accompanying file LICENSE_1_0.txt or copy at
0006 // http://www.boost.org/LICENSE_1_0.txt
0007 //
0008 // See http://boostorg.github.com/compute for more information.
0009 //---------------------------------------------------------------------------//
0010
0011 #ifndef BOOST_COMPUTE_ALGORITHM_REMOVE_IF_HPP
0012 #define BOOST_COMPUTE_ALGORITHM_REMOVE_IF_HPP
0013
0014 #include <boost/static_assert.hpp>
0015
0016 #include <boost/compute/system.hpp>
0017 #include <boost/compute/algorithm/copy_if.hpp>
0018 #include <boost/compute/container/vector.hpp>
0019 #include <boost/compute/functional/logical.hpp>
0020 #include <boost/compute/type_traits/is_device_iterator.hpp>
0021
0022 namespace boost {
0023 namespace compute {
0024
0025 /// Removes each element for which \p predicate returns \c true in the
0026 /// range [\p first, \p last).
0027 ///
0028 /// Space complexity: \Omega(3n)
0029 ///
0030 /// \see remove()
0031 template<class Iterator, class Predicate>
0032 inline Iterator remove_if(Iterator first,
0033                           Iterator last,
0034                           Predicate predicate,
0035                           command_queue &queue = system::default_queue())
0036 {
0037     BOOST_STATIC_ASSERT(is_device_iterator<Iterator>::value);
0038     typedef typename std::iterator_traits<Iterator>::value_type value_type;
0039
0040     // temporary storage for the input data
0041     ::boost::compute::vector<value_type> tmp(first, last, queue);
0042
0043     return ::boost::compute::copy_if(tmp.begin(),
0044                                      tmp.end(),
0045                                      first,
0046                                      not1(predicate),
0047                                      queue);
0048 }
0049
0050 } // end compute namespace
0051 } // end boost namespace
0052
0053 #endif // BOOST_COMPUTE_ALGORITHM_REMOVE_IF_HPP