why nostd::unique_ptr<Scope> not Scope

[halayli]

Any reason why WithActiveSpan returns nostd::unique_ptr<Scope> instead of simply returning Scope?

[lalitb]

Scope object manages the ongoing span context, and context unwinding happens when this object goes out of scope. It's important to have only one copy of this object, so it's wrapped under nostd::unique_ptr.

Also, if it's meant to be a question and not an issue we can move it to Discussions

[halayli]

I totally get the purpose of a span's Scope and its integration with the Context's internal Stack. But I don't understand why it needs to be allocated on the heap. It's a performance penalty that can be avoided, IMO. A scope class with deleted copy constructors should be enough. In fact for this particular case, they are implicitly deleted because it has a std::unique_ptr member variable.

It's definitely a question and not an issue. Sorry, I forgot about the discussion feature. Feel free to move it there.

[lalitb]

We can keep it open for now in case it's a potential issue :) For now, will let @pyohannes reply at his work time as he originally implemented this. Else, will look into it.

[halayli]

Sounds great, thanks!

[lalitb]

@halayli @pyohannes - Have raised a PR #788 with changes suggested in the issue. Can you please review them once?

[halayli]

Thanks for taking care of it! Yep, this should do it.