Compare the execution time with a mix of valid and invalid values.

compare.rs

use std::time::Instant;

fn main() {
    let mut valid = 0;
    let start = Instant::now();
    for i in 0..=0x7fff_ffff_u32 {
        let cell = 0x0880_0000_001f_ffff | (u64::from(i) << 21);
        let is_valid = h3cell::is_valid_h3(cell);

        valid += is_valid as usize;
    }
    let duration = start.elapsed();
    println!("found {} valid cells in {:?}", valid, duration);

    let mut valid = 0;
    let start = Instant::now();
    for i in 0..=0x7fff_ffff_u32 {
        let cell = 0x0880_0000_001f_ffff | (u64::from(i) << 21);
        let is_valid = unsafe { h3ron_h3_sys::h3IsValid(cell) != 0 };

        valid += is_valid as usize;
    }
    let duration = start.elapsed();
    println!("found {} valid cells in {:?}", valid, duration);
}