Self-describing numbers

You are encouraged to solve this task according to the task description, using any language you may know.
There are several so-called "self-describing" or "self-descriptive" integers.

An integer is said to be "self-describing" if it has the property that, when digit positions are labeled 0 to N-1, the digit in each position is equal to the number of times that that digit appears in the number.

For example,   2020   is a four-digit self describing number:

   position   0   has value   2   and there are two 0s in the number;
   position   1   has value   0   and there are no 1s in the number;
   position   2   has value   2   and there are two 2s;
   position   3   has value   0   and there are zero 3s.


Self-describing numbers < 100.000.000  are:     1210,   2020,   21200,   3211000,   42101000.



Task Description
 Write a function/routine/method/... that will check whether a given positive integer is self-describing.
 As an optional stretch goal - generate and display the set of self-describing numbers.


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fn is_self_desc(xx: u64) -> bool
{
    let s: String = xx.to_string();
    let mut count_vec = vec![0; 10];
    for c in s.chars() {
        count_vec[c.to_digit(10).unwrap() as usize] += 1;
    }
    for (i, c) in s.chars().enumerate() {
        if count_vec[i] != c.to_digit(10).unwrap() as usize {
            return false;
        }
    }
    return true;
}
 
fn main() {
    for i in 1..100000000 {
        if is_self_desc(i) {
            println!("{}", i)
        }
    }
}
 