for: replace range() function with range notation

[genbattle]

I was updating old code of mine and got this warning for one of my code files:

main.rs:15:14: 15:19 warning: use of unstable item: will be replaced by range notation, #[warn(unstable)] on by default
main.rs:15     for i in range(1, 1000) {

I pulled up Rust by Example to see what the new idiomatic way of doing this was and found that Rust by Example was using the same (apparently unstable) syntax. The Rust book also uses the outdated syntax.

So at the moment there's no straightforward up-to-date resources on what the syntax should be. But apparently it involves Rust's new [a..b] range syntax. Can someone with more knowledge about what the syntax should be please update Rust by Example.

[genbattle]

It looks like this is a fairly new change. I also discovered by wading through various github issues for Rust that the new syntax for basic for loops using numeric ranges is:

for i in a..b {

[genbattle]

Also apparently brackets are required in some cases but not in others?

for i in (a..b) {

[vayn]

I encountered this warning in Rust book, too. Thanks for sharing the information @genbattle

[mdinger]

for i in (a..b) {is just a bug. I think rust-lang/rust#21396 is a fix. I think I fixed this in #421 if it's accepted.

[anderspitman]

Is there any way to avoid this warning when using a variable in the range? ie

let a = [i32; 10];
for i in range(0, a.len()) {}

[mdinger]

fn main() {
    let a: [i32; 2] = [1, 2] ;
    for i in 0..a.len() {
        println!("{:?}", i);
    }
}