Index and IndexMut documentation could be improved

[Cobrand]

Index and IndexMut are definitely lacking in explanations.

For starters, nothing says what does v[x] do exactly. (spoilers : it's sugar for *v.index(x) and *v.index_mut(x) and not v.index(x) ; that allows things like v[x] = 5).

Index<usize> is implemented for lots of trivial types (str, String, Vec, ...), but nothing is said about Index<Range...>, and I think it would be worth showing some examples.

I'm opening this, but I'm planning to open a PR next week fixing this, unless someone else is up for it of course.

[marti1125]

Hi @Cobrand I would like to work in this =D

[Cobrand]

@marti1125 Then go ahead 👍 !

[marti1125]

@Cobrand I don't know how to start =/

[Cobrand]

Well, I could help of course, but I think you are mistaken about me; I'm not a mentor or anything, just a perfectly average contributor, so my help will be quite limited: I wouldn't like to lead you the wrong way.

I guess you could start by writing in pure english what I've described up there, and minimum requirement would be :

• Explain what v[x] does (litterally a subtitute of *v.index(x) and *v.index_mut(x) if an lvalue is needed).
• Adding examples of usages of v[x] (v[x] = 5, let f : &i64 = &v[x], things like this)
• Adding examples for .index(range), for instance v[..5] if v is a slice, will return the first 5 elements as a slice. (Do the same thing with slice mut).
• Use your imagination for creative examples

Again sorry if I misled you, I'm not a mentor in any way

[steveklabnik]

, just a perfectly average contributor, so my help will be quite limited

I actually think this means that you have a great deal of ability to help; often, more experienced contributors won't realize that an explanation is too advanced, or that something is missing.

All of these seem like great improvements to me.

[Cobrand]

@marti1125 do you still want to work on this ?