progress

gpx-rs/src/core/statistics/utils.rs

@@ -0,0 +1,44 @@
+use std::ops::Add;
+
+pub fn combine_options<T>(a: Option<T>, b: Option<T>, f: impl FnOnce(T, T) -> T) -> Option<T> {
+    match (a, b) {
+        (Some(a), Some(b)) => Some(f(a, b)),
+        (Some(v), None) | (None, Some(v)) => Some(v),
+        (None, None) => None,
+    }
+}
+
+pub fn sum_options<T>(a: Option<T>, b: Option<T>) -> Option<T>
+where
+    T: Add<Output = T>,
+{
+    combine_options(a, b, |a, b| a + b)
+}
+
+pub fn min_options<T>(a: Option<T>, b: Option<T>) -> Option<T>
+where
+    T: Ord,
+{
+    combine_options(a, b, |a, b| a.min(b))
+}
+
+pub fn max_options<T>(a: Option<T>, b: Option<T>) -> Option<T>
+where
+    T: Ord,
+{
+    combine_options(a, b, |a, b| a.max(b))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_sum_options() {
+        assert_eq!(sum_options(Some(1), Some(2)), Some(3));
+        assert_eq!(sum_options(Some(1), None), Some(1));
+        assert_eq!(sum_options(None, Some(2)), Some(2));
+        assert_eq!(sum_options::<i32>(None, None), None);
+        assert_eq!(sum_options(Some(0.5), Some(0.25)), Some(0.75));
+    }
+}