checked_iterator Class
The checked_iterator class allows you to transform an iterator into a checked iterator.
For a list of all members of this type, see checked_iterator Members.
注意
This class is a Microsoft extension to the Standard C++ Library. Code implemented using this algorithm will not be portable.
template <class _Cont, class _Iter = typename _Cont::iterator>
class checked_iterator : public iterator<
typename iterator_traits<_Iter>::iterator_category,
typename iterator_traits<_Iter>::value_type,
typename iterator_traits<_Iter>::difference_type,
typename iterator_traits<_Iter>::pointer,
typename iterator_traits<_Iter>::reference>
;
Remarks
This class is defined in the stdext namespace.
This iterator adapter should only be used when you have a non-checked iterator. All Standard C++ Library containers will return a checked iterator if _SECURE_SCL is set to 1, so there is no need to use checked_iterator with std::vector<T>::iterator, for example. However, if you have a custom container which returns iterators that are non-checked, then use checked_iterator.
If your code relies heavily on non-Standard C++ Library containers and iterators and you do not want to use checked_iterator, then consider disabling these warnings using _SCL_SECURE_NO_WARNINGS or the other methods described in that topic.
For more information, see Checked Iterators.
Example
The following code sample shows how to use a function that enforces the use of checked iterators without defining _SECURE_SCL. This requires you to explicitly define checked iterators, for all iterators used by checked functions.
// checked_iterators.cpp
// compile with: /EHsc
#include <vector>
#include <list>
#include <numeric>
#include <functional>
#include <iostream>
int main() {
using namespace std;
vector<int> V1( 10 ), V2( 10 );
vector<int>::iterator VIter1, VIter2, VIterend, VIterend2;
stdext::checked_iterator< vector<int> > VChkIterend(V1, V1.begin());
stdext::checked_iterator< vector<int> > VChkIterend2(V2, V2.begin());
list<int> L1;
stdext::checked_iterator< list<int> > LChkIterend(L1, L1.begin());
list<int>::iterator LIter1, LIterend;
int t;
for ( t = 1 ; t <= 10 ; t++ )
L1.push_back( t );
cout << "The input list L1 is:\n ( " ;
for ( LIter1 = L1.begin() ; LIter1 != L1.end() ; LIter1++ )
cout << *LIter1 << " ";
cout << ")." << endl;
// The first member function for the partial sums of
// elements in a list output to a vector
stdext::checked_iterator< vector<int> > V1chkbegin(V1, V1.begin());
VChkIterend = stdext::checked_partial_sum ( L1.begin(), L1.end(), V1chkbegin );
cout << "The output vector containing the partial sums is:\n ( " ;
for ( VIter1 = V1.begin( ) ; VIter1 != VChkIterend.base() ; VIter1++ )
cout << *VIter1 << " ";
cout << ")." << endl;
// The second member function used to compute
// the partial product of the elements in a list
stdext::checked_iterator< vector<int> > V2chkbegin(V2, V2.begin());
VChkIterend2 = stdext::checked_partial_sum ( L1.begin(), L1.end(), V2chkbegin ,
multiplies<int>( ) );
cout << "The output vector with the partial products is:\n ( " ;
for ( VIter2 = V2.begin() ; VIter2 != VChkIterend2.base() ; VIter2++ )
cout << *VIter2 << " ";
cout << ")." << endl;
// Computation of partial sums in place
stdext::checked_iterator< list<int> > L1chkbegin(L1, L1.begin());
LChkIterend = stdext::checked_partial_sum ( L1.begin ( ) , L1.end ( ) , L1chkbegin );
cout << "The in place output stdext::checked_partial_sum list L1 is:\n ( " ;
for ( LIter1 = L1.begin( ) ; LIter1 != LChkIterend.base() ; LIter1++ )
cout << *LIter1 << " ";
cout << ")." << endl;
}
The input list L1 is:
( 1 2 3 4 5 6 7 8 9 10 ).
The output vector containing the partial sums is:
( 1 3 6 10 15 21 28 36 45 55 ).
The output vector with the partial products is:
( 1 2 6 24 120 720 5040 40320 362880 3628800 ).
The in place output stdext::checked_partial_sum list L1 is:
( 1 3 6 10 15 21 28 36 45 55 ).
Requirements
Header: <iterator>
Namespace: stdext