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//---------------------------------------------------------------------------//
// 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.
//---------------------------------------------------------------------------//
#include <iostream>
#include <iterator>
#include <boost/compute/algorithm/max_element.hpp>
#include <boost/compute/container/vector.hpp>
#include <boost/compute/functional/geometry.hpp>
#include <boost/compute/iterator/transform_iterator.hpp>
#include <boost/compute/types/fundamental.hpp>
namespace compute = boost::compute;
// this example shows how to use the max_element() algorithm along with
// a transform_iterator and the length() function to find the longest
// 4-component vector in an array of vectors
int main()
{
using compute::float4_;
// vectors data
float data[] = { 1.0f, 2.0f, 3.0f, 0.0f,
4.0f, 5.0f, 6.0f, 0.0f,
7.0f, 8.0f, 9.0f, 0.0f,
0.0f, 0.0f, 0.0f, 0.0f };
// create device vector with the vector data
compute::vector<float4_> vector(
reinterpret_cast<float4_ *>(data),
reinterpret_cast<float4_ *>(data) + 4
);
// find the longest vector
compute::vector<float4_>::const_iterator iter =
compute::max_element(
compute::make_transform_iterator(
vector.begin(), compute::length<float4_>()
),
compute::make_transform_iterator(
vector.end(), compute::length<float4_>()
)
).base();
// print the index of the longest vector
std::cout << "longest vector index: "
<< std::distance(vector.begin(), iter)
<< std::endl;
return 0;
}
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