Rust has string formatting.
fn main() {
let a = "AAA";
let b = format!("BBB {}", a);
println(b);
}
// output: BBB AAA
In the Rust version, there is no additional repetition but you must explicitly call format!()
and the inserted values are separated from the string. This is basically the same way that Python and C# developers are used to doing things, and the rationale is that this technique makes it easier to localize code into other languages.
The Rust mailing list has an archived discussion ([rust-dev] Suggestions) in which the different types of string interpolation are discussed.