Before Rust 1.0, we removed the ~str syntax for owned strings. I don't want that syntax back, but its immediate replacement was named StrBuf, which we changed to String shortly after. If I could go back in time, I'd keep StrBuf.
Also, here's a Rust closure: || {}
Here's a Ruby closure: {|| }
Given that we took the syntax from Ruby, I kind of wish we'd kept it identical; it gets very confusing when I switch back and forth.