make_checked_array_iterator

Creates a checked_array_iterator that can be used by other algorithms.

template <class Iter>
  checked_array_iterator<Iter> 
    make_checked_array_iterator(
      Iter Ptr,
      size_t Size,
      size_t Index = 0
);

Parameters

• Ptr
  A pointer to the destination array.

• Size
  The size of the destination array.

• Index
  Optional index into the array.

Return Value

An instance of checked_array_iterator.

Remarks

The make_checked_array_iterator function is defined in the stdext namespace.

This function takes a raw pointer—which would ordinarily cause concern about bounds overrun—and wraps it in a checked_array_iterator class that does checking. Because that class is marked as checked, the STL doesn't warn about it. For more information and code examples, see Checked Iterators.

Example

In the following example, a vector is created and populated with 10 items. The contents of the vector are copied into an array by using the copy algorithm, and then make_checked_array_iterator is used to specify the destination. This is followed by an intentional violation of the bounds checking so that a debug assertion failure is triggered.

// make_checked_array_iterator.cpp
// compile with: /EHsc /W4 /MTd

#include <algorithm>
#include <iterator> // stdext::make_checked_array_iterator
#include <memory> // std::make_unique
#include <iostream>
#include <vector>
#include <string>

using namespace std;

template <typename C> void print(const string& s, const C& c) {
    cout << s;

    for (const auto& e : c) {
        cout << e << " ";
    }

    cout << endl;
}

int main()
{
    const size_t dest_size = 10;
    // Old-school but not exception safe, favor make_unique<int[]>
    // int* dest = new int[dest_size];
    unique_ptr<int[]> updest = make_unique<int[]>(dest_size);
    int* dest = updest.get(); // get a raw pointer for the demo

    vector<int> v;

    for (int i = 0; i < dest_size; ++i) {
        v.push_back(i);
    }
    print("vector v: ", v);

    copy(v.begin(), v.end(), stdext::make_checked_array_iterator(dest, dest_size));

    cout << "int array dest: ";
    for (int i = 0; i < dest_size; ++i) {
        cout << dest[i] << " ";
    }
    cout << endl;

    // Add another element to the vector to force an overrun.
    v.push_back(10);
    // The next line causes a debug assertion when it executes.
    copy(v.begin(), v.end(), stdext::make_checked_array_iterator(dest, dest_size));
}

Output

vector v: 0 1 2 3 4 5 6 7 8 9
int array dest: 0 1 2 3 4 5 6 7 8 9

Requirements

Header: <iterator>

Namespace: stdext

See Also

Reference

Standard Template Library