fill


Category: algorithms	Component type: function

Prototype

template <class ForwardIterator
class T>
void fill(ForwardIterator first
ForwardIterator last
const T& value);

Description

Fill assigns the value value to every element in the range [first last). That is for every iterator i in [first last) it performs the assignment *i = value.

Definition

Defined in the standard header algorithm and in the nonstandard backward-compatibility header algo.h.

Requirements on types

ForwardIterator is a model of Forward Iterator. [1]
ForwardIterator is mutable.
T is a model of Assignable.
T is convertible to Forward Iterator's value type.

Preconditions

[first last) is a valid range.

Complexity

Linear. Fill performs exactly last - first assignments.

Example

vector<double> V(4);
fill(V.begin()
V.end()
137);
assert(V[0] == 137 && V[1] == 137 && V[2] == 137 && V[3] == 137);

Notes

[1] The reason that fill requires its argument to be a mutable forward iterator rather than merely an output iterator is that it uses a range [first last) of iterators. There is no sensible way to describe a range of output iterators because it is impossible to compare two output iterators for equality. The fill_n algorithm does have an interface that permits use of an output iterator.