Rustdoc: No mention of copy trait for primitive types

[azerupi]

As a new rust user I have struggled with a little problem: http://stackoverflow.com/questions/30540419/rust-ownership-copy-clone-trait

The ownership and borrowing rules are well explained in the docs but the copy trait and the types that implement them are not!

In the doc http://doc.rust-lang.org/std/marker/trait.Copy.html primitive types are not listed as copy trait implementors. They should at least be mentioned there.

It would be good to also add a little more info here: http://doc.rust-lang.org/book/ownership.html#copy-types Maybe give some examples like in my question on stackoverflow:

The following two snippets of code only compile because i32 and bool types both implement the copy trait. Meaning that the ownership is not moved by default but copied instead

fn main() {
    let a = 5;

    let _y = double(a);
    println!("{}", a);
}

fn double(x: i32) -> i32 {
    x * 2
}

fn main() {
    let a = true;

    let _y = change_truth(a);
    println!("{}", a);
}

fn change_truth(x: bool) -> bool {
    !x
}

This is very important since it is an exception to the most important rule of the language

Let me know if I have to make a pull request with a "change proposal" :)

[steveklabnik]

Triage: no real change.

[shepmaster]

This continues to confuse newcomers.

[steveklabnik]

@mbrubeck points out that str is not Copy https://play.rust-lang.org/?gist=a7e12362ef93f657e7f23f411637e879&version=stable

[scottmcm]

This just confused me for the stable-soon never type, where I think it's likely that even experienced rustaceans would be wondering about implemented traits.

[shepmaster]

PR #48171 is working on it 😉

[vext01]

Is it me, or do the docs still not mention the Copy trait in (e.g.) usize and ptr?

[shepmaster]

do the docs still not mention the Copy

Rust has a release cadence of 6 weeks. That commit was merged on Apr 4, starting on the nightly release. Rust 1.26 stable was released on Thu May 10 2018 and this was promoted to beta. You can see Copy in those docs.

Rust 1.27 stable will be released on Thu Jun 21 2018, at which time this will show up in those docs.