make_unchecked_array_iterator
Creates an unchecked_array_iterator that can be used by other algorithms.
Note
This function is a Microsoft extension of the Standard C++ Library. Code implemented by using this function is not portable to C++ Standard build environments that do not support this Microsoft extension.
template <class Iter>
unchecked_array_iterator<Iter>
make_unchecked_array_iterator(
Iter Ptr
);
Parameters
- Ptr
A pointer to the destination array.
Return Value
An instance of unchecked_array_iterator.
Remarks
The make_unchecked_array_iterator function is defined in the stdext namespace.
This function takes a raw pointer and wraps it in a class that performs no checking and therefore optimizes away to nothing, but it also silences compiler warnings such as C4996. Therefore, this is a targeted way to deal with unchecked-pointer warnings without globally silencing them or incurring the cost of checking. 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_unchecked_array_iterator is used to specify the destination.
// make_unchecked_array_iterator.cpp
// compile with: /EHsc /W4 /MTd
#include <algorithm>
#include <iterator> // stdext::make_unchecked_array_iterator
#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;
int *dest = new int[dest_size];
vector<int> v;
for (int i = 0; i < dest_size; ++i) {
v.push_back(i);
}
print("vector v: ", v);
// COMPILER WARNING SILENCED: stdext::unchecked_array_iterator is marked as checked in debug mode
// (it performs no checking, so an overrun will trigger undefined behavior)
copy(v.begin(), v.end(), stdext::make_unchecked_array_iterator(dest));
cout << "int array dest: ";
for (int i = 0; i < dest_size; ++i) {
cout << dest[i] << " ";
}
cout << endl;
delete[] dest;
}
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