For example, I've been doing a lot of Rust coding. The code in question looks like: iter.next().ok_or(ErrorKind::NotEnoughArguments.into())?.parse().chain

For example, I've been doing a lot of Rust coding. The code in question looks like: iter.next().ok_or(ErrorKind::NotEnoughArguments.into())?.parse().chain_err(|| "cannot parse argument")? the compiler responds with cannot infer type information for `_` the solution is of course to do iter.next().ok_or::<Error>(ErrorKind::NotEnoughArguments.into())?.parse().chain_err(|| "cannot parse argument")? then the type inference is decidable in a dynamic language, you wouldn't have to worry about this; in fact, you wouldn't need to call .into() either - there's just less typing and compiler errors