/usr/include/boost/compute/algorithm/detail
Edit: /usr/include/boost/compute/algorithm/detail/count_if_with_reduce.hpp (2648B)
//---------------------------------------------------------------------------//
// Copyright (c) 2013 Kyle Lutz
//
// 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_ALGORITHM_DETAIL_COUNT_IF_WITH_REDUCE_HPP
#define BOOST_COMPUTE_ALGORITHM_DETAIL_COUNT_IF_WITH_REDUCE_HPP
#include
#include
#include
namespace boost {
namespace compute {
namespace detail {
template
struct invoked_countable_predicate
{
invoked_countable_predicate(Predicate p, Arg a)
: predicate(p), arg(a)
{
}
Predicate predicate;
Arg arg;
};
template
inline meta_kernel& operator<<(meta_kernel &kernel,
const invoked_countable_predicate &expr)
{
return kernel << "(" << expr.predicate(expr.arg) << " ? 1 : 0)";
}
// the countable_predicate wraps Predicate and converts its result from
// bool to ulong so that it can be used with reduce()
template
struct countable_predicate
{
typedef ulong_ result_type;
countable_predicate(Predicate predicate)
: m_predicate(predicate)
{
}
template
invoked_countable_predicate operator()(const Arg &arg) const
{
return invoked_countable_predicate(m_predicate, arg);
}
Predicate m_predicate;
};
// counts the number of elements matching predicate using reduce()
template
inline size_t count_if_with_reduce(InputIterator first,
InputIterator last,
Predicate predicate,
command_queue &queue)
{
countable_predicate reduce_predicate(predicate);
ulong_ count = 0;
::boost::compute::reduce(
::boost::compute::make_transform_iterator(first, reduce_predicate),
::boost::compute::make_transform_iterator(last, reduce_predicate),
&count,
::boost::compute::plus(),
queue
);
return static_cast(count);
}
} // end detail namespace
} // end compute namespace
} // end boost namespace
#endif // BOOST_COMPUTE_ALGORITHM_DETAIL_COUNT_IF_WITH_REDUCE_HPP