Rust requires trait bounds (its equivalent of concepts) to type-check the template code at definition site, when it's written, not at the instantiation site whe

Rust requires trait bounds (its equivalent of concepts) to type-check the template code at definition site, when it's written, not at the instantiation site where it's used. This results in much better error messages. The downside is that trait bounds for numeric code are awfully verbose, and you can't sneak in a printf without declaring it as a requirement.