C++ valarray Library - Function begin

Description

It returns an iterator pointing to the first element in the valarray x.

Declaration

Following is the declaration for std::valarray::begin function.

template <class T> /*unspecified1*/ begin (valarray<T>& x);

C++11

template <class T> /*unspecified1*/ begin (valarray<T>& x);

Parameters

x − It is a valarray objects.

Return Value

It returns an iterator pointing to the first element in the valarray x.

Exceptions

Basic guarantee − if any operation performed on the elements throws an exception.

Data races

All elements effectively copied are accessed.

Example

In below example explains about std::valarray::begin function.

#include <iostream>
#include <valarray>

int main () {
   std::valarray<int> sam {0,10,20,30,40};

   std::cout << "sam contains:";
   for (auto it = begin(sam); it!=end(sam); ++it)
      std::cout << ' ' << *it;
   std::cout << '\n';

   return 0;
}

Let us compile and run the above program, this will produce the following result −

sam contains: 0 10 20 30 40