Break day 3 into modules

day_03/src/op.rs

@@ -0,0 +1,52 @@
+use core::ops::Mul;
+use std::str::FromStr;
+
+/// Multiple Operation
+#[derive(Debug)]
+pub struct MulOp {
+    lhs: String,
+    rhs: String,
+}
+
+impl MulOp {
+    pub fn new(lhs: String, rhs: String) -> MulOp {
+        MulOp { lhs, rhs }
+    }
+
+    pub fn multiple<T>(&self) -> Result<<T as Mul>::Output, <T as FromStr>::Err>
+    where
+        T: FromStr + Mul,
+    {
+        let lhs: T = self.lhs.parse()?;
+        let rhs: T = self.rhs.parse()?;
+        Ok(lhs * rhs)
+    }
+}
+
+/// Do Operation
+#[derive(Debug)]
+pub struct DoOp {}
+
+impl DoOp {
+    pub fn new() -> DoOp {
+        DoOp {}
+    }
+}
+
+/// Don't Operation
+#[derive(Debug)]
+pub struct DontOp {}
+
+impl DontOp {
+    pub fn new() -> DontOp {
+        DontOp {}
+    }
+}
+
+/// Enum of all Operations
+#[derive(Debug)]
+pub enum Ops {
+    Mul(MulOp),
+    Do(DoOp),
+    Dont(DontOp),
+}