exterior mutability -> inherited mutability, another useful link, warn about transmute

[rust-101.git] / workspace / src / part08.rs

diff --git a/workspace/src/part08.rs b/workspace/src/part08.rs
index d03934a8a023b6827f2c9298ccd9bca51d9fc0dd..01189060eb1b958256583d0eb1717bcc94319976 100644 (file)
--- a/workspace/src/part08.rs
+++ b/workspace/src/part08.rs
@@ -7,7 +7,7 @@ use part05::BigInt;
 
 // So, let us write a function to "add with carry", and give it the appropriate type. Notice Rust's native support for pairs.
 fn overflowing_add(a: u64, b: u64, carry: bool) -> (u64, bool) {
 
 // So, let us write a function to "add with carry", and give it the appropriate type. Notice Rust's native support for pairs.
 fn overflowing_add(a: u64, b: u64, carry: bool) -> (u64, bool) {

-    let sum = u64::wrapping_add(a, b);
+    let sum = a.wrapping_add(b);

     // If an overflow happened, then the sum will be smaller than *both* summands. Without an overflow, of course, it will be
     // at least as large as both of them. So, let's just pick one and check.
     if sum >= a {
     // If an overflow happened, then the sum will be smaller than *both* summands. Without an overflow, of course, it will be
     // at least as large as both of them. So, let's just pick one and check.
     if sum >= a {


@@ -15,7 +15,7 @@ fn overflowing_add(a: u64, b: u64, carry: bool) -> (u64, bool) {
         // **Exercise 08.1**: Write the code to handle adding the carry in this case.
         unimplemented!()
     } else {
         // **Exercise 08.1**: Write the code to handle adding the carry in this case.
         unimplemented!()
     } else {

-        // The addition *did* overflow. It is impossible for the addition of the carry
+        // Otherwise, the addition *did* overflow. It is impossible for the addition of the carry

         // to overflow again, as we are just adding 0 or 1.
         unimplemented!()
     }
         // to overflow again, as we are just adding 0 or 1.
         unimplemented!()
     }


@@ -76,7 +76,9 @@ impl<'a, 'b> ops::Add<&'a BigInt> for &'b BigInt {
 // Rust calls a bunch of definitions that are grouped together a *module*. You can put the tests in a submodule as follows.
 #[cfg(test)]
 mod tests {
 // Rust calls a bunch of definitions that are grouped together a *module*. You can put the tests in a submodule as follows.
 #[cfg(test)]
 mod tests {

-    #[test]
+    use part05::BigInt;
+
+    /*#[test]*/

     fn test_add() {
         let b1 = BigInt::new(1 << 32);
         let b2 = BigInt::from_vec(vec![0, 1]);
     fn test_add() {
         let b1 = BigInt::new(1 << 32);
         let b2 = BigInt::from_vec(vec![0, 1]);