dynamic array c++ without pointer

Question

Is it possible to create a dynamic array in c++ without using a pointer explicitly(int array[] instead of int* array)?

ie. something like this:

int size = 5;
int array[];

array = new int{size};

for (int i = 0; i < size; i++)
{
    array[i];
}

You're probably aware of it, but could you not use **std::vector** for this purpose? — Blitzkoder, Oct 11 '12 at 21:01
Related - [Variable length arrays in C++?](http://stackoverflow.com/questions/1887097/variable-length-arrays-in-c) — Joe, Oct 11 '12 at 21:02
What are you trying to achieve? You would still have to free it manually, the only difference would be the syntax. Also have look at `std::array`. — Karel Petranek, Oct 11 '12 at 21:03
Why do you want to do this? I don't get it. You're also implying that you could maybe somehow use a pointer implicitly? What does that even mean? — David Titarenco, Oct 11 '12 at 21:06

score 2 · Accepted Answer · answered Oct 11 '12 at 21:08

2

Yes, of course, it is possible:

#include <iostream>
int main()
{
    [](int array[] = new int[10]) {
        std::cout << "array = " << array << "\n";
        delete[] array;
    }();
}

answered Oct 11 '12 at 21:08

Dietmar Kühl

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Well, yes - but it is using the required notation! ;) – Dietmar Kühl Oct 11 '12 at 21:16
This might do what OP asked, but it's kludgey. Seriously, just use a vector. – jakev Oct 12 '12 at 20:43

score 0 · Answer 2 · answered Oct 11 '12 at 21:02

0

In short, no. The compiler needs to know the size of the array, so to use stack allocated arrays in c++, it must be specified in the declaration. I recommend you look at the STL Vector class instead.

answered Oct 11 '12 at 21:02

jakev

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bames53 · Answer 3 · 2012-10-11T21:21:06.070

0

int array[]; necessarily has automatic storage duration (in a function or class scope) and cannot have dynamic storage duration.

You can hide the pointer inside a class like std::vector<int>.

You could do something like

int (&array)[5] = reinterpret_cast<int(&)[5]>(*new int[5]);

to delete: delete [] array;

edited Oct 11 '12 at 21:21

answered Oct 11 '12 at 21:03

bames53

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That's terrifying. Also will leak unless `delete`d in a similar manner. – Mooing Duck Oct 11 '12 at 21:17
To delete it you just need the address of the first element, and to get that you can rely on the automatic conversion for arrays. – bames53 Oct 11 '12 at 21:21

score 0 · Answer 4 · answered Oct 11 '12 at 21:07

You can do it using a reference:

#include <iostream>
using namespace std;

int main()
{
   int& val = *(new int[2]);
   val = 1;
   *(&val + 1) = 2;

   cout << val << ' ' << *(&val+1)  << '\n';

   delete [] (&val);

   return 0;
}

But as you can see, this is not very readable and would be very prone to error. Best bet would be to just use std::vector.

score 0 · Answer 5 · answered Oct 11 '12 at 21:10

0

No, but you can use dynamic types from std library, like std::vector.

The type std::vector acting very similar to array.

Look at this std::vector.

answered Oct 11 '12 at 21:10

nrofis

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dynamic array c++ without pointer

5 Answers5