iota


Category: algorithms	Component type: function

Prototype

template <class ForwardIterator, class T>
void iota(ForwardIterator first, ForwardIterator last, T value);

Description

Iota assigns sequentially increasing values to a range. That is, it assigns value to *first, value + 1 to *(first + 1) and so on. In general, each iterator i in the range [first, last) is assigned value + (i - first). [1]

Definition

Defined in the standard header numeric, and in the nonstandard backward-compatibility header algo.h. This function is an SGI extension; it is not part of the C++ standard.

Requirements on types

ForwardIterator is a model of Forward Iterator.
ForwardIterator is mutable.
T is Assignable.
If x is an object of type T, then x++ is defined.
T is convertible to ForwardIterator's value type.

Preconditions

[first, last) is a valid range.

Complexity

Linear. Exactly last - first assignments.

Example

int main()
{
  vector<int> V(10);

  iota(V.begin(), V.end(), 7);
  copy(V.begin(), V.end(), ostream_iterator<int>(cout, " "));
  cout << endl; 
}

Notes

[1] The name iota is taken from the programming language APL.