如何减少cuda中的元组（也返回一个元组？）>

Question

说我有一个由两个thrust::device_vector组成的元组。我希望输出是一个由两个标量组成的元组，它们分别是两个向量的总和。例如，

input tuple consisting of two vectors:
a: 3, 5, 2 
b: 6, 1, 7
output tuple consisting of two scalars:
10
14
我认为这应该非常容易，但是我仍然不知道这样做的方法。我的代码

#include <iostream>
#include <stdlib.h>
#include <thrust/device_vector.h>
#include <thrust/reduce.h>
#include <thrust/transform.h>
#include <thrust/tuple.h>
#include <thrust/transform_reduce.h>
#include <thrust/iterator/zip_iterator.h>

template<typename T>
struct TestTuplePlus
{
    __host__ __device__
    thrust::tuple<T, T> operator()(thrust::tuple<T, T>& t0, thrust::tuple<T, T>& t1)
    {
            return thrust::make_tuple(thrust::get<0>(t0) + thrust::get<0>(t1), thrust::get<1>(t0) + thrust::get<1>(t1));
    }
};

int main()
{
  thrust::device_vector<float> a(3, 0);
  thrust::device_vector<float> b(3, 0);

  a[0] = 3;
  a[1] = 5;
  a[2] = 2;
  b[0] = 6;
  b[1] = 1;
  b[2] = 7;

  auto begin = thrust::make_zip_iterator(thrust::make_tuple(a.begin(), b.begin()));
  auto end = thrust::make_zip_iterator(thrust::make_tuple(a.end(), b.end()));

  // reduce to a tuple
  thrust::tuple<float, float> result = thrust::reduce(begin, end, thrust::make_tuple<float,float>(0,0), TestTuplePlus<float>()); // produce compilation error

  return 0;
}
编译错误：

/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/detail/function.h(96): error: function "TestTuplePlus<T>::operator() [with T=float]" cannot be called with the given argument list
            argument types are: (thrust::tuple<float, float, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>, thrust::detail::tuple_of_iterator_references<float &, float &, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>)
            object type is: TestTuplePlus<float>
          detected during:
            instantiation of "Result thrust::detail::wrapped_function<Function, Result>::operator()(Argument1 &, const Argument2 &) const [with Function=TestTuplePlus<float>, Result=thrust::tuple<float, float, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>, Argument1=thrust::tuple<float, float, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>, Argument2=thrust::detail::tuple_of_iterator_references<thrust::device_reference<float>, thrust::device_reference<float>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>]" 
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/system/detail/sequential/reduce.h(61): here
            instantiation of "OutputType thrust::system::detail::sequential::reduce(thrust::system::detail::sequential::execution_policy<DerivedPolicy> &, InputIterator, InputIterator, OutputType, BinaryFunction) [with DerivedPolicy=thrust::detail::seq_t, InputIterator=thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, OutputType=thrust::tuple<float, float, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>, BinaryFunction=TestTuplePlus<float>]" 
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/detail/reduce.inl(71): here
            instantiation of "T thrust::reduce(const thrust::detail::execution_policy_base<DerivedPolicy> &, InputIterator, InputIterator, T, BinaryFunction) [with DerivedPolicy=thrust::detail::seq_t, InputIterator=thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, T=thrust::tuple<float, float, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>, BinaryFunction=TestTuplePlus<float>]" 
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/system/cuda/detail/reduce.h(1022): here
            instantiation of "T thrust::cuda_cub::reduce_n(thrust::cuda_cub::execution_policy<Derived> &, InputIt, Size, T, BinaryOp) [with Derived=thrust::cuda_cub::tag, InputIt=thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, Size=signed long, T=thrust::tuple<float, float, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>, BinaryOp=TestTuplePlus<float>]" 
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/system/cuda/detail/reduce.h(1037): here
            instantiation of "T thrust::cuda_cub::reduce(thrust::cuda_cub::execution_policy<Derived> &, InputIt, InputIt, T, BinaryOp) [with Derived=thrust::cuda_cub::tag, InputIt=thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, T=thrust::tuple<float, float, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>, BinaryOp=TestTuplePlus<float>]" 
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/detail/reduce.inl(71): here
            instantiation of "T thrust::reduce(const thrust::detail::execution_policy_base<DerivedPolicy> &, InputIterator, InputIterator, T, BinaryFunction) [with DerivedPolicy=thrust::cuda_cub::tag, InputIterator=thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, T=thrust::tuple<float, float, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>, BinaryFunction=TestTuplePlus<float>]" 
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/detail/reduce.inl(186): here
            instantiation of "T thrust::reduce(InputIterator, InputIterator, T, BinaryFunction) [with InputIterator=thrust::zip_iterator<thrust::tuple<thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::detail::normal_iterator<thrust::device_ptr<float>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, T=thrust::tuple<float, float, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>, BinaryFunction=TestTuplePlus<float>]" 
老实说，我不知道如何解决它。

我实际上找到了这个post，但我也没有对其进行编译。

无论如何，有一种简单的方法可以减少cuda中的元组吗？

说我有一个由两个推力:: device_vector组成的元组。我希望输出是一个由两个标量组成的元组，它们分别是两个向量的总和。例如，输入元组...

Answer 1

奇怪的是，由于推力实际上将第一个和第二个参数的元组类型传递给函子，因此产生了编译错误。可以从这种差异中得出：