Book 4.1 should mention that shadowing does not destroy the original value.

[MichaelNecio]

In reading about shadowing I was curious if shadowing a binding within the same scope would cause a destructor to be called, which I did eventually find is not the case https://www.reddit.com/r/rust/comments/2eelew/unexpected_for_me_behavior/?ref=share&ref_source=link, but perhaps this should be mentioned in the book to prevent incorrect assumptions from being formed (it's happened at least once).

There is currently an example of a binding being shadowed in a new scope and then the old value being used again, but I don't think this is enough for people to make the connection that shadowing never destroys a value ( they could think that the compiler keeps track of whether or not a binding is used again in the same scope ).

[steveklabnik]

I am not working on the book at the moment, given that I'm working on the second edition. If someone wants to send me a PR for this, I'd take it, though!

[steveklabnik]

this was closed by #34125