memento: Fix memory leak

[jclsn]

The memento should be deleted after it is restored.

In a real example you would probably use std::shared_ptr for this, but I see the advantage of not using too many advanced data structures when teaching about patterns.

[neochief]

Thanks!

[jclsn]

You are welcome! Thank you for the great book! I really enjoy reading it and the examples in many different languages a great! Had to laugh hard about the hippie joke btw😄Am 13.03.2025 um 10:31 schrieb Alexander Shvets ***@***.***>: Thanks!—Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you authored the thread.Message ID: ***@***.***> neochief left a comment (RefactoringGuru/design-patterns-cpp#12) Thanks! —Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you authored the thread.Message ID: ***@***.***>

[neochief]

@jclsn May I ask you for a favour? Can you check out this PR and see whether it's any good? #6

I'm not a C++ developer, so I can only rely on people like you to keep these examples decent.

[jclsn]

I am still a C++ noob as well and am also a Linux user. I booted a Windows VM though to check. The only necessary change in that commit is the one for the Facade. GCC does automatically deduce the empty branch in the ternary, but MVSC does throw an error. The author of the commit himself said that he had aggressive warnings turned on. I don't think it should be necessary to fix all of those.

Other things I have noticed:

• There is an #include<memory> missing in Strategy -> Does compile in MSVC as it automatically adds the misisng include, but not in GCC.
• The ThreadSafe examples of Singleton have a memory leak as well, as the destructor is protected and there is no DeleteSingleton() method that could be called at the end of main.
• Strategy is the only example using smart pointers, although this isn't used in any other example, which isn't consistent. Smart pointers are actually state of the art to handle memory in modern C++, but I think are out of the scope of the book. I tried a Udemy course on Design Patterns some years ago that used smart pointers and templates even, which I found quite overwhelming for a beginner.

[neochief]

@jclsn Thanks!