Rename sheet folders to assure proper sorting

aufgaben/sheet06/sol1/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "sol1"
+version = "0.1.0"
+authors = ["Lukas Kalbertodt <lukas.kalbertodt@gmail.com>"]
+
+[dependencies]

aufgaben/sheet06/sol1/src/lib.rs

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+use std::ops::{Add, Mul};
+
+#[cfg(test)]
+mod tests;
+
+
+/// Clamps a value into a given range. This function returns the value closest
+/// to `value` which lies in between `min` and `max`.
+///
+/// *Note*: it's not clear whether `PartialOrd` or `Ord` is the correct bound
+/// here. With `PartialEq`, some results may look strange to some.
+/// `clamp(NaN, 0.0, 5.0)` would return `NaN` for example. `NaN` as min or max
+/// wouldn't do anything.
+pub fn clamp<T>(value: T, min: T, max: T) -> T
+    where T: PartialOrd
+{
+    // This is a small little trick. We want to avoid using if-else here, so
+    // we match the unit value `()` (void) and use the match guards.
+    match () {
+        () if value < min => min,
+        () if value > max => max,
+        _ => value,
+    }
+}
+
+
+/// Returns the sum and the product of the two given parameters.
+///
+/// *Note*: Either a Clone or Copy bound is necessary. Clone was choosen here,
+/// because it's more general.
+pub fn sum_product<T, U>(a: T, b: U)
+    -> (<T as Add<U>>::Output, <T as Mul<U>>::Output)
+    where T: Add<U> + Mul<U> + Clone,
+          U: Clone
+{
+    (a.clone() + b.clone(), a * b)
+}
+
+/// Extension trait for simple conversion from `bool` to `Option<T>`
+pub trait BoolOptionExt {
+    /// If `self` is `true`, `Some(value)` is returned, `None` otherwise.
+    fn into_option<T>(self, value: T) -> Option<T>;
+}
+
+impl BoolOptionExt for bool {
+    fn into_option<T>(self, value: T) -> Option<T> {
+        match self {
+            true => Some(value),
+            false =>  None,
+        }
+    }
+}

aufgaben/sheet06/sol1/src/tests.rs

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+#[test]
+fn clamp() {
+    use clamp;
+
+    assert_eq!(clamp(3,  5, 10), 5);
+    assert_eq!(clamp(6,  5, 10), 6);
+    assert_eq!(clamp(11, 5, 10), 10);
+
+    assert_eq!(clamp(3.0,  5.0, 10.0), 5.0);
+    assert_eq!(clamp(6.0,  5.0, 10.0), 6.0);
+    assert_eq!(clamp(11.0, 5.0, 10.0), 10.0);
+}
+
+#[test]
+fn sum_product() {
+    use sum_product;
+
+    assert_eq!(sum_product(3, 4), (7, 12));
+    assert_eq!(sum_product(3.0, 4.0), (7.0, 12.0));
+}
+
+#[test]
+fn bool_option() {
+    use BoolOptionExt;
+
+    assert_eq!(false.into_option(3), None);
+    assert_eq!( true.into_option(3), Some(3));
+}