i
[_ ; n]
This does NOT break any existing programs because the `[_, ..n]` syntax is also supported.
Additionally, add lots of tests for new functionality around statics and `static mut`.
int
f64
floating point numbers for real. This will break code that looks like: let mut x = 0; while ... { x += 1; } println!("{}", x); Change that code to: let mut x = 0i; while ... { x += 1; } println!("{}", x); Closes #15201. [breaking-change]