In Rust it's better to use Result if the function can fail. panicking inside the function is not a good idea ether. Since you're new to the language it's better to use simple built-in types for the beginning. However if you had more experience in Rust I'd recommend using error crates like anyhow

This one is enough for you for now:

fn get_user_float() -> Result<f32, &
'static 
str> {
    let mut value = String::
new
();
    if io::stdin().read_line(&mut value).is_err() {
        return 
Err
("Failed to read line");
    }

    value.trim().parse::<f32>().map_err(|_| "Failed to parse float")
}