public member function

std::valarray::valarray

<valarray>
valarray();
explicit valarray (size_t n);
valarray (const T& val, size_t n);
valarray (const T* p, size_t n);
valarray (const valarray& x);
valarray (const slice_array<T>& sub);
valarray (const gslice_array<T>& sub);
valarray (const mask_array<T>& sub);
valarray (const indirect_array<T>& sub);
valarray constructor
Constructs a valarray object.

Parameters

n
Length of array.
If this is the only parameter, the elements are constructed with their default constructor.
size_t is an unsigned integral type.
val
Value to which each of the elements is initialized.
T is the template type of valarray (the elements' type).
p
Pointer to an array of elements. The first n elements are used as initial values for the elements in the valarray.
T is the template type of valarray (the elements' type).
x
A valarray object.
The elements in *this are initialized to copies of the elements in x. The resulting length matches that of x.
sub
The result of a valarray subscripting operation.
The elements in *this are initialized to copies of the elements in sub. The resulting length matches that of sub.

Example

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// valarray constructor example
#include <iostream>
#include <valarray>
using namespace std;

int main ()
{
  int init[]= {10,20,30,40};
  valarray<int> first;           // (empty)
  valarray<int> second (5);      // 0 0 0 0 0
  valarray<int> third (10,3);    // 10 10 10
  valarray<int> fourth (init,4); // 10 20 30 40
  valarray<int> fifth (fourth);  // 10 20 30 40

  cout << "fifth sums " << fifth.sum() << endl;

  return 0;
}


Output:

fifth sums 100

See also