copy
Assigns the values of elements from a source range to a destination range, iterating through the source sequence of elements and assigning them new positions in a forward direction.
template<class InputIterator, class OutputIterator>
OutputIterator copy(
InputIterator _First,
InputIterator _Last,
OutputIterator _DestBeg
);
매개 변수
_First
소스배포 범위에서 첫 번째 요소의 위치를 가리키는 입력 반복기입니다._Last
An input iterator addressing the position that is one past the final element in the source range._DestBeg
An output iterator addressing the position of the first element in the destination range.
반환 값
An output iterator addressing the position that is one past the final element in the destination range, that is, the iterator addresses _Result + (_Last – _First ).
설명
원본 범위 유효 해야하고 복사하고 모든 요소를 대상에 충분한 공간이 있어야 합니다.
Because the algorithm copies the source elements in order beginning with the first element, the destination range can overlap with the source range provided the _Last position of the source range is not contained in the destination range. copy can be used to shift elements to the left but not the right, unless there is no overlap between the source and destination ranges. To shift to the right any number of positions, use the copy_backward algorithm.
The copy algorithm only modifies values pointed to by the iterators, assigning new values to elements in the destination range. 새 요소를 만드는 데 사용할 수 없고 빈 컨테이너에 요소가 직접 삽입할 수 없습니다.
copy은 두 가지 관련된 폼이 있습니다.
이러한 기능이 동작하는 방식에 대한 자세한 내용은 Checked Iterators을 참조하십시오.
예제
// alg_copy.cpp
// compile with: /EHsc
#include <vector>
#include <algorithm>
#include <iostream>
int main() {
using namespace std;
vector <int> v1, v2;
vector <int>::iterator Iter1, Iter2;
int i;
for ( i = 0 ; i <= 5 ; i++ )
v1.push_back( 10 * i );
int ii;
for ( ii = 0 ; ii <= 10 ; ii++ )
v2.push_back( 3 * ii );
cout << "v1 = ( " ;
for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
cout << *Iter1 << " ";
cout << ")" << endl;
cout << "v2 = ( " ;
for ( Iter2 = v2.begin( ) ; Iter2 != v2.end( ) ; Iter2++ )
cout << *Iter2 << " ";
cout << ")" << endl;
// To copy the first 3 elements of v1 into the middle of v2
copy( v1.begin( ), v1.begin( ) + 3, v2.begin( ) + 4 );
cout << "v2 with v1 insert = ( " ;
for ( Iter2 = v2.begin( ) ; Iter2 != v2.end( ) ; Iter2++ )
cout << *Iter2 << " ";
cout << ")" << endl;
// To shift the elements inserted into v2 two positions
// to the left
copy( v2.begin( )+4, v2.begin( ) + 7, v2.begin( ) + 2 );
cout << "v2 with shifted insert = ( " ;
for ( Iter2 = v2.begin( ) ; Iter2 != v2.end( ) ; Iter2++ )
cout << *Iter2 << " ";
cout << ")" << endl;
}
For another sample showing how to use copy, see accumulate, copy 및 vector::push_back.
Output
v1 = ( 0 10 20 30 40 50 )
v2 = ( 0 3 6 9 12 15 18 21 24 27 30 )
v2 with v1 insert = ( 0 3 6 9 0 10 20 21 24 27 30 )
v2 with shifted insert = ( 0 3 0 10 20 10 20 21 24 27 30 )
요구 사항
헤더: <algorithm>
네임스페이스: std