Indeed, in the later case, exceptions are really an unnecessary cost. In fact, another argument which could be made against the use of exceptions is that the a

Indeed, in the later case, exceptions are really an unnecessary cost. In fact, another argument which could be made against the use of exceptions is that the abstraction per se is not a really good mechanism for abstracting error handling. Explicitly handling errors - including try!() à la Rust and/or monadic composition of functions - usually leads to a better error coverage, as safety is enforced by the type system itself.