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 parame-
ters, 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.