I might have mis-interpreted this statement: "Certain types and traits that exist in the standard library are known to the Rust compiler."
(https://doc.rust-lang.org/reference/special-types-and-traits...")
In terms of syntax, you create a box with Box::new just like you might any other struct.
EDIT: anyway I'm not saying that means that your underlying issue isn't real, just that I think describing it as "syntax" makes the issue confusing to understand. It sounds to me like maybe you think Rust programs are too verbose?