thrust::uninitialized_fill_n

Defined in thrust/uninitialized_fill.h

template<typename DerivedPolicy, typename ForwardIterator, typename Size, typename T>
ForwardIterator thrust::uninitialized_fill_n(const thrust::detail::execution_policy_base<DerivedPolicy> &exec, ForwardIterator first, Size n, const T &x)

In thrust, the function thrust::device_new allocates memory for an object and then creates an object at that location by calling a constructor. Occasionally, however, it is useful to separate those two operations. If each iterator in the range [first, first+n) points to uninitialized memory, then uninitialized_fill creates copies of x in that range. That is, for each iterator i in the range [first, first+n), uninitialized_fill creates a copy of x in the location pointed to i by calling ForwardIterator's value_type's copy constructor.

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

The following code snippet demonstrates how to use uninitialized_fill to initialize a range of uninitialized memory using the thrust::device execution policy for parallelization:

#include <thrust/uninitialized_fill.h>
#include <thrust/device_malloc.h>
#include <thrust/execution_policy.h>

struct Int
{
  __host__ __device__
  Int(int x) : val(x) {}
  int val;
};
...
const int N = 137;

Int val(46);
thrust::device_ptr<Int> array = thrust::device_malloc<Int>(N);
thrust::uninitialized_fill_n(thrust::device, array, N, val);

// Int x = array[i];
// x.val == 46 for all 0 <= i < N

See also

https://en.cppreference.com/w/cpp/memory/uninitialized_fill

See also

uninitialized_fill

See also

fill

See also

uninitialized_copy_n

See also

device_new

See also

device_malloc

Parameters

• exec – The execution policy to use for parallelization.

• first – The first element of the range of interest.

• n – The size of the range of interest.

• x – The value to use as the exemplar of the copy constructor.

Template Parameters

• DerivedPolicy – The name of the derived execution policy.

• ForwardIterator – is a model of Forward Iterator, ForwardIterator is mutable, and ForwardIterator's value_type has a constructor that takes a single argument of type T.

Returns

first+n