testCargoTwo/
lib.rs

1pub fn add(left: usize, right: usize) -> usize {
2    left + right
3}
4
5
6
7// feature-demo/src/png.rs
8#[cfg(feature = "png")]
9pub fn process_png() {
10    println!("Processing png");
11}
12
13// feature-demo/src/webp.rs
14#[cfg(feature = "webp")]
15pub fn process_webp() {
16    process_png();
17    println!("Processing webp");
18}
19
20#[cfg(test)]
21mod tests {
22    use super::*;
23
24    #[test]
25    fn it_works() {
26        let result = add(2, 2);
27        assert_eq!(result, 4);
28    }
29}