June 2018 Update

Task/Man-or-boy-test/Rust/man-or-boy-test.rust

@@ -0,0 +1,39 @@
+use std::cell::Cell;
+
+trait Arg {
+    fn run(&self) -> i32;
+}
+
+impl Arg for i32 {
+    fn run(&self) -> i32 { *self }
+}
+
+struct B<'a> {
+    k: &'a Cell<i32>,
+    x1: &'a Arg,
+    x2: &'a Arg,
+    x3: &'a Arg,
+    x4: &'a Arg,
+}
+
+impl<'a> Arg for B<'a> {
+    fn run(&self) -> i32 {
+        self.k.set(self.k.get() - 1);
+        a(self.k.get(), self, self.x1, self.x2, self.x3, self.x4)
+    }
+}
+
+fn a(k: i32, x1: &Arg, x2: &Arg, x3: &Arg, x4: &Arg, x5: &Arg) -> i32 {
+    if k <= 0 {
+        x4.run() + x5.run()
+    } else {
+        B{
+            k: &Cell::new(k),
+            x1, x2, x3, x4
+        }.run()
+    }
+}
+
+pub fn main() {
+    println!("{}", a(10, &1, &-1, &-1, &1, &0));
+}