Question on safety of returning a string reference in `resolve`

[ravern]

Not trying to report a bug, just curious how some of the code here works. Thanks in advance, and no pressure on answering this quickly!

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In the following lines, the comment asserts that it is safe to return a reference to the string because we know it will never be moved.

https://github.com/mwillsey/symbol_table/blob/d521c91691bf208ef625f16f3d6bc75c2f7390be/src/lib.rs#L176-L181

However, in the following lines, strs.push is called, which I expect might copy the contents of the Vec to a new location should the Vec need to be grown. I couldn't find any other code to handle this case.

https://github.com/mwillsey/symbol_table/blob/d521c91691bf208ef625f16f3d6bc75c2f7390be/src/lib.rs#L97-L98

My question is just whether there's something I missed here? Or is my assumption that Vec copies its contents wrong?

[mwillsey]

You are correct that Vec might move its contents around, but the string doesn't sit in the vec! The Vec holds Strings (well, actually Box<str>s), and that additional layer of indirection is what makes this safe.

[ravern]

That makes so much sense, thanks!