tune Makefile for less pointless rebuilding

[rust-101.git] / workspace / src / part07.rs

diff --git a/workspace/src/part07.rs b/workspace/src/part07.rs
index 0130637b7a83c853880c9126c2b3287099f62e07..3ea4cc089e1679bd9e5de2a12fc34d0b85d350dc 100644 (file)
--- a/workspace/src/part07.rs
+++ b/workspace/src/part07.rs
@@ -1,5 +1,3 @@
-// ***Remember to enable/add this part in `main.rs`!***
-

 // Rust-101, Part 07: Operator Overloading, Tests, Formatting
 // ==========================================================
 
 // Rust-101, Part 07: Operator Overloading, Tests, Formatting
 // ==========================================================
 


@@ -13,14 +11,17 @@ pub trait Minimum {
 pub fn vec_min<T: Minimum>(v: &Vec<T>) -> Option<&T> {
     let mut min: Option<&T> = None;
     for e in v {
 pub fn vec_min<T: Minimum>(v: &Vec<T>) -> Option<&T> {
     let mut min: Option<&T> = None;
     for e in v {

-        unimplemented!()
+        min = Some(match min {
+            None => e,
+            Some(n) => n.min(e)
+        });

     }
     min
 }
 
 // **Exercise 07.1**: For our `vec_min` to be usable with `BigInt`, you will have to provide an implementation of
 // `Minimum`. You should be able to pretty much copy the code you wrote for exercise 06.1. You should *not*
     }
     min
 }
 
 // **Exercise 07.1**: For our `vec_min` to be usable with `BigInt`, you will have to provide an implementation of
 // `Minimum`. You should be able to pretty much copy the code you wrote for exercise 06.1. You should *not*

-// make any copies!
+// make any copies of `BigInt`!

 impl Minimum for BigInt {
     fn min<'a>(&'a self, other: &'a Self) -> &'a Self {
         unimplemented!()
 impl Minimum for BigInt {
     fn min<'a>(&'a self, other: &'a Self) -> &'a Self {
         unimplemented!()


@@ -60,7 +61,7 @@ fn test_min() {
 
 // ## Formatting
 
 
 // ## Formatting
 

-// All formating is handled by [`std::fmt`](http://doc.rust-lang.org/std/fmt/index.html). I won't explain
+// All formating is handled by [`std::fmt`](https://doc.rust-lang.org/std/fmt/index.html). I won't explain

 // all the details, and refer you to the documentation instead.
 use std::fmt;
 
 // all the details, and refer you to the documentation instead.
 use std::fmt;