Standard C++ Library
Copyright 1998, Rogue Wave Software, Inc.

NAME

 
fill, fill_n
 
 - Initializes a range with a given value.
 
 
 

SYNOPSIS

#include <algorithm>
template <class ForwardIterator, class T>

void fill(ForwardIterator first, ForwardIterator last,

const T& value);

 
template <class OutputIterator, class Size, class T>

void fill_n(OutputIterator first, Size n, const T& value);
 
 
 

DESCRIPTION

 
 
The fill and fill_n algorithms are used to assign a value to the elements in a sequence. fill assigns the value to all the elements designated by iterators in the range [first, last). 
 
The fill_n algorithm assigns the value to all the elements designated by iterators in the range [first, first + n). fill_n assumes that there are at least n elements following first, unless first is an insert iterator. 
 
Type T must be Assignable, and Size must be convertible to an integral type. 
 
 
 

COMPLEXITY

 
 
fill makes exactly last - first assignments, and fill_n makes exactly n assignments. 
 
 
 

EXAMPLE

//
// fill.cpp
//

#include <algorithm>
#include <vector>
#include <iostream>

using namespace std;
 
int main()

{

int d1[4] = {1,2,3,4};

//
// Set up two vectors
//

vector<int> v1(d1,d1 + 4), v2(d1,d1 + 4);

//
// Set up one empty vector
//

vector<int> v3;

//
// Fill all of v1 with 9
//
fill(v1.begin(),v1.end(),9);

//
// Fill first 3 of v2 with 7
//
fill_n(v2.begin(),3,7);

//
// Use insert iterator to fill v3 with 5 11’s
//
fill_n(back_inserter(v3),5,11);
//
// Copy all three to cout
//

ostream_iterator<int,char> out(cout," ");
copy(v1.begin(),v1.end(),out);
cout << endl;
copy(v2.begin(),v2.end(),out);
cout << endl;
copy(v3.begin(),v3.end(),out);
cout << endl;

//
// Fill cout with 3 5’s
//
fill_n(ostream_iterator<int,char>(cout," "),3,5);

cout << endl;

return 0;

}
 

Program Output
 
 
 

 
9 9 9 9
7 7 7 4
11 11 11 11 11
5 5 5
 
 
 

WARNINGS

 
 
If your compiler does not support default template parameters, then you always need to supply the Allocator template argument. For instance, you have to write:
 
vector<int,allocator<int> >
 
instead of:
 
vector<int>
 
If your compiler does not support namespaces, then you do not need the using declaration for std. 
 

Rogue Wave Software  —  Last change: 02 Apr 1998