Algorithm
Copies a range of elements
#include <algorithm>
template <class InputIterator, class OutputIterator>
OutputIterator copy(InputIterator first, InputIterator last,
OutputIterator result);
template <class BidirectionalIterator1, class BidirectionalIterator2>
BidirectionalIterator2 copy_backward(BidirectionalIterator1 first,
BidirectionalIterator1 last,
BidirectionalIterator2 result);
The copy algorithm copies values from the range specified by [first , last) to the range that specified by [result, result + (last - first)). copy can be used to copy values from one container to another, or to copy values from one location in a container to another location in the same container, as long as result is not within the range [first-last). copy returns result + (last - first). For each non-negative integer n < (last - first), copy assigns *(first + n) to *(result + n). The result of copy is undefined if result is in the range [first, last).
Unless result is an insert iterator, copy assumes that at least as many elements follow result as are in the range [first, last).
The copy_backward algorithm copies elements in the range specified by [first, last) into the range specified by [result - (last - first), result), starting from the end of the sequence (last-1) and progressing to the front (first). Note that copy_backward does not reverse the order of the elements, it simply reverses the order of transfer. copy_backward returns result - (last - first). You should use copy_backward instead of copy when last is in the range [result - (last - first), result). For each positive integer n <= (last - first), copy_backward assigns *(last - n) to *(result - n). The result of copy_backward is undefined if result is in the range [first, last).
Unless result is an insert iterator, copy_backward assumes that there are at least as many elements ahead of result as are in the range [first, last).
Both copy and copy_backward perform exactly last - first assignments.
//
// stdlib/examples/manual.copyex.cpp
//
#include <algorithm>
#include <vector>
#include <iostream.h>
int main()
{
int d1[4] = {1,2,3,4};
int d2[4] = {5,6,7,8};
// Set up three vectors
//
vector<int> v1(d1,d1 + 4), v2(d2,d2 + 4), v3(d2,d2 + 4);
//
// Set up one empty vector
//
vector<int> v4;
//
// Copy v1 to v2
//
copy(v1.begin(),v1.end(),v2.begin());
//
// Copy backwards v1 to v3
//
copy_backward(v1.begin(),v1.end(),v3.end());
//
// Use insert iterator to copy into empty vector
//
copy(v1.begin(),v1.end(),back_inserter(v4));
//
// Copy all four to cout
//
ostream_iterator<int> 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;
copy(v4.begin(),v4.end(),out);
cout << endl;
return 0;
}
Output :
1 2 3 4
1 2 3 4
1 2 3 4
1 2 3 4
If your compiler does not support default template parameters then you need to always supply the Allocator template argument. For instance you'll have to write:
vector <int, allocator>
instead of:
vector <int>