error-stack: how is Context stored?

[Abhicodes-crypto]

In the current_context function I see that C: `static lifetime. Does that mean C is stored for the entire runtime of the process.

PS: I'm new to rust

[TimDiekmann]

Hi @Abhicodes-crypto and thanks for the question!

C internally is stored as Box<dyn Any> inside of Report. This means that C is stored on the heap and will be deallocated as soon as Report goes out of scope.

A little bit of context; C requires 'static because of two reasons:

• If C wouldn't be 'static, the lifetime would bubble up to Report, so it would become something like Report<'a, C>. As Report typically is used as a return value from a function, dealing with lifetimes is hard, the main issue, however, is that
• the exact type of C is not known anymore at compile time. To allow downcasting C, it's required, that C is 'static as Any is implemented for any T where T: 'static. If I remember correctly there are a few attempts to allow Any to have any lifetime but this is a bit ... tricky.

I hope this can answer your question 🙂