thrust::for_each#

Overloads#

for_each(exec, first, last, f)#

template<typename DerivedPolicy, typename InputIterator, typename UnaryFunction>
InputIterator thrust::for_each(
const thrust::detail::execution_policy_base<DerivedPolicy> &exec,
InputIterator first,
InputIterator last,
UnaryFunction f,
)#

for_each applies the function object f to each element in the range [first, last); f's return value, if any, is ignored. Unlike the C++ Standard Template Library function std::for_each, this version offers no guarantee on order of execution. For this reason, this version of for_each does not return a copy of the function object.

The algorithm’s execution is parallelized as determined by exec.

The following code snippet demonstrates how to use for_each to print the elements of a thrust::device_vector using the thrust::device parallelization policy:

#include <thrust/for_each.h>
#include <thrust/device_vector.h>
#include <thrust/execution_policy.h>
#include <cstdio>
...

struct printf_functor
{
  __host__ __device__
  void operator()(int x)
  {
    // note that using printf in a __device__ function requires
    // code compiled for a GPU with compute capability 2.0 or
    // higher (nvcc --arch=sm_20)
    printf("%d\n", x);
  }
};
...
thrust::device_vector<int> d_vec(3);
d_vec[0] = 0; d_vec[1] = 1; d_vec[2] = 2;

thrust::for_each(thrust::device, d_vec.begin(), d_vec.end(), printf_functor());

// 0 1 2 is printed to standard output in some unspecified order

See also

for_each_n

See also

https://en.cppreference.com/w/cpp/algorithm/for_each

Parameters:

  • exec – The execution policy to use for parallelization.

  • first – The beginning of the sequence.

  • last – The end of the sequence.

  • f – The function object to apply to the range [first, last).

Template Parameters:

  • DerivedPolicy – The name of the derived execution policy.

  • InputIterator – is a model of Input Iterator, and InputIterator's value_type is convertible to UnaryFunction's argument type.

  • UnaryFunction – does not apply any non-constant operation through its argument.

Returns:

last

for_each(first, last, f)#

template<typename InputIterator, typename UnaryFunction>
InputIterator thrust::for_each(
InputIterator first,
InputIterator last,
UnaryFunction f,
)#

for_each applies the function object f to each element in the range [first, last); f's return value, if any, is ignored. Unlike the C++ Standard Template Library function std::for_each, this version offers no guarantee on order of execution. For this reason, this version of for_each does not return a copy of the function object.

The following code snippet demonstrates how to use for_each to print the elements of a device_vector.

#include <thrust/for_each.h>
#include <thrust/device_vector.h>
#include <stdio.h>

struct printf_functor
{
  __host__ __device__
  void operator()(int x)
  {
    // note that using printf in a __device__ function requires
    // code compiled for a GPU with compute capability 2.0 or
    // higher (nvcc --arch=sm_20)
    printf("%d\n", x);
  }
};
...
thrust::device_vector<int> d_vec(3);
d_vec[0] = 0; d_vec[1] = 1; d_vec[2] = 2;

thrust::for_each(d_vec.begin(), d_vec.end(), printf_functor());

// 0 1 2 is printed to standard output in some unspecified order

See also

for_each_n

See also

https://en.cppreference.com/w/cpp/algorithm/for_each

Parameters:

  • first – The beginning of the sequence.

  • last – The end of the sequence.

  • f – The function object to apply to the range [first, last).

Template Parameters:

  • InputIterator – is a model of Input Iterator, and InputIterator's value_type is convertible to UnaryFunction's argument type.

  • UnaryFunction – does not apply any non-constant operation through its argument.

Returns:

last