err

err(value)

• Casts T into Err<T>
• Casts Promise<T> into ErrP<T>
• Forwards any Result type as-is

err(true); //=> Err<boolean>
err(Promise.resolve(true)); //=> ErrP<boolean>
err(ok(true)); //=> Ok<boolean>
err(err(true)); //=> Err<boolean>
err(okP(true)); //=> OkP<boolean>
err(errP(true)); //=> ErrP<boolean>