...but we also don't want the lines to get too long

[rust-101.git] / src / part05.rs

diff --git a/src/part05.rs b/src/part05.rs
index b593360122a7ba8beb277a494f2e3eb48c555056..6780ca306002e08a8b01312af83ecc7494dd4d4e 100644 (file)
--- a/src/part05.rs
+++ b/src/part05.rs
@@ -48,8 +48,10 @@ impl BigInt {
     }
 
     // We can convert any vector of digits into a number, by removing trailing zeros. The `mut`
-    // declaration for `v` here is just like the one in `let mut ...`, it says that we will locally
-    // change the vector `v`.
+    // declaration for `v` here is just like the one in `let mut ...`: We completely own `v`, but Rust
+    // still asks us to make our intention of modifying it explicit. This `mut` is *not* part of the
+    // type of `from_vec` - the caller has to give up ownership of `v` anyway, so they don't care anymore
+    // what you do to it.
     // 
     // **Exercise 05.1**: Implement this function.
     // 
@@ -145,4 +147,4 @@ fn work_on_variant(mut var: Variant, text: String) {
 //@ I hope this example clarifies why Rust has to rule out mutation in the presence of aliasing *in general*,
 //@ not just for the specific case of a buffer being reallocated, and old pointers becoming hence invalid.
 
-//@ [index](main.html) | [previous](part04.html) | [next](part06.html)
+//@ [index](main.html) | [previous](part04.html) | [raw source](https://www.ralfj.de/git/rust-101.git/blob_plain/HEAD:/workspace/src/part05.rs) | [next](part06.html)