Tuple indexing syntax is missing from the rust book

[andreabedini]

It seems tuple indexing syntax is not introduced anywhere in the current documentation.

It shows up briefly here http://doc.rust-lang.org/nightly/reference.html#tuple-types as

assert!(p.0 == 10);

but nowhere else.

I think it should be introduced both there and here http://doc.rust-lang.org/nightly/book/compound-data-types.html#tuples

I'd help with some text but but there's nothing I hate more than writing :)

ping @steveklabnik

[steveklabnik]

I thought I had this in somewhere, but maybe I don't