X-Git-Url: https://git.ralfj.de/rust-101.git/blobdiff_plain/8fcdbed310c53f621fba0401399659ed1a1ec446..83e8dbfff2a6fdce785af58dbb13f007c4234cf2:/src/part08.rs

diff --git a/src/part08.rs b/src/part08.rs
index 7a9c093..d6b6782 100644
--- a/src/part08.rs
+++ b/src/part08.rs
@@ -26,7 +26,9 @@ fn overflowing_add(a: u64, b: u64, carry: bool) -> (u64, bool) {
     if sum >= a {
         // The addition did not overflow. <br/>
         // **Exercise 08.1**: Write the code to handle adding the carry in this case.
-        unimplemented!()
+        let sum_total = u64::wrapping_add(sum, if carry { 1 } else { 0 });      /*@@*/
+        let had_overflow = sum_total < sum;                                     /*@@*/
+        (sum_total, had_overflow)                                               /*@@*/
     } else {
         // 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.
@@ -82,7 +84,10 @@ impl ops::Add<BigInt> for BigInt {
             carry = new_carry;                                                  /*@*/
         }
         // **Exercise 08.2**: Handle the final `carry`, and return the sum.
-        unimplemented!()
+        if carry {                                                              /*@@*/
+            result_vec.push(1);                                                 /*@@*/
+        }                                                                       /*@@*/
+        BigInt { data: result_vec }                                             /*@@*/
     }
 }