Instantiating a struct with stdin data in Rust

I am very, very new to Rust and trying to implement some simple things to get the feel for the language. Right now, I'm stumbling over the best way to implement a class-like struct that involves casting a string to an int. I'm using a global-namespaced function and it feels wrong to my Ruby-addled brain.

What's the Rustic way of doing this?

use std::io;

struct Person {
  name: ~str,
  age: int
}

impl Person {  
  fn new(input_name: ~str) -> Person {
    Person { 
      name: input_name, 
      age: get_int_from_input(~"Please enter a number for age.")
    }
  }

  fn print_info(&self) {
    println(fmt!("%s is %i years old.", self.name, self.age));
  }

}

fn get_int_from_input(prompt_message: ~str) -> int {
  println(prompt_message);
  let my_input = io::stdin().read_line();
  let my_val =
    match from_str::<int>(my_input) {
      Some(number_string)   => number_string,
      _                     => fail!("got to put in a number.")
  };

  return my_val;
}


fn main() {
  let first_person = Person::new(~"Ohai");
  first_person.print_info();
}

This compiles and has the desired behaviour, but I am at a loss for what to do here--it's obvious I don't understand the best practices or how to implement them.

Edit: this is 0.8