"999 is enough for anybody" triple-zero padding (#18)

When I hit 999 exercises, I will finally have reached the ultimate
state of soteriological release and no more exercises will be needed.
The cycle will be complete. All that will be left is perfect quietude,
freedom, and highest happiness.

exercises/019_functions2.zig

@@ -0,0 +1,30 @@
+//
+// Now let's create a function that takes a parameter. Here's an
+// example that takes two parameters. As you can see, parameters
+// are declared just like any other types ("name": "type"):
+//
+//     fn myFunction(number: u8, is_lucky: bool) {
+//         ...
+//     }
+//
+const std = @import("std");
+
+pub fn main() void {
+    std.debug.print("Powers of two: {} {} {} {}\n", .{
+        twoToThe(1),
+        twoToThe(2),
+        twoToThe(3),
+        twoToThe(4),
+    });
+}
+
+// Please give this function the correct input parameter(s).
+// You'll need to figure out the parameter name and type that we're
+// expecting. The output type has already been specified for you.
+//
+fn twoToThe(???) u32 {
+    return std.math.pow(u32, 2, my_number);
+    // std.math.pow(type, a, b) takes a numeric type and two numbers
+    // of that type and returns "a to the power of b" as that same
+    // numeric type.
+}