Shared Pointers and Arrays

Before C++17

Only unique_ptr was able to handle arrays out of the box (without the need to define a custom deleter).

After C++17

Now it’s also possible with shared_ptr as shown below:

std::shared_ptr<int[]> ptr(new int[10]);

Please note that std::make_shared doesn’t support arrays in C++17. However, this will be fixed in C++20 (see P0674 which is already merged into C++20)

Another important remark is that raw arrays should be avoided. It’s usually better to use standard containers. However, sometimes, you don’t have the luxury to use vectors or lists - for example:

• in an embedded environment
• or when you work with third-party API

In that situation, you might end up with a raw pointer to an array. With C++17, you’ll be able to wrap those pointers into smart pointers (std::unique_ptr or std::shared_ptr) and be sure the memory is deleted correctly.

Extra Info: See the initial proposal: P0414R2.

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Next up, we’ll tackle three new generic functions which have been introduced for data structures.