Ch. 3.1 Structures - unclear lifetime comment

[singalen]

The code in the chapter includes a generic argument ’a with a comment “The ‘a defined a lifetime”
The chapter refers a “Lifetimes” chapter.
Problem: there is nothing in “Lifetimes” explaining this syntax or its meaning. Quite opposite, it says: “ no names or types are assigned to label lifetimes”.

[xiaochuanyu]

So the 'a thing is kinda explained in a subsection of Lifetime here https://doc.rust-lang.org/nightly/rust-by-example/scope/lifetime/explicit.html. Might be a good idea for Structures's see also section to to link to it instead.

Also, the example could have just avoided lifetime annotations all together by using String instead just like the Rust book here https://doc.rust-lang.org/book/ch05-01-defining-structs.html.