two dimensional array with shared_ptr

Question

I need a two dimensional array filled with instances of different derived types my code looks like this:

std::array<std::array<std::shared_ptr<Base>, 1>, 1> b;
b[1][1] = std::shared_ptr<Base>(new Derived(x, y));

The code compiles but there is some form of memory leak in std::__shared_weak_count::__release_shared() during the execution of the second line.

My question is: How can I properly create a two dimensional array of derived classes?

Just like T a[1][1]; a[1][1] = v; is going out of bounds, your code is going out of bounds as well. — Sarfaraz Nawaz
– Sarfaraz Nawaz, Commented Apr 24, 2015 at 9:36
[OT]: You may directly use std::make_shared<Derived>(x, y) instead of std::shared_ptr<Base>(new Derived(x, y)) — Jarod42
– Jarod42, Commented Apr 24, 2015 at 11:54

TobiMcNamobi · Accepted Answer · 2015-04-24 09:58:36Z

1

As mentioned in the comments b[1] is out of bounds in your example.

In general an std::array (as well as C-array, std::vector, and others) of length n allows you to use indices 0, .., n - 1 on it.

answered Apr 24, 2015 at 9:58

TobiMcNamobi

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