From 3712439caf5e469a5cccc22eb5f4cb0a854be379 Mon Sep 17 00:00:00 2001
From: jayber <james.a.bromley@gmail.com>
Date: Tue, 7 Jun 2022 13:39:54 +0100
Subject: [PATCH] feat: improved closure docs and exercises by using
 into_iter()

---
 exercises/closures/closures5.rs | 3 +++
 exercises/closures/closures7.rs | 2 +-
 info.toml                       | 8 +++++---
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/exercises/closures/closures5.rs b/exercises/closures/closures5.rs
index d4dddf62..4f97d735 100644
--- a/exercises/closures/closures5.rs
+++ b/exercises/closures/closures5.rs
@@ -21,6 +21,9 @@ fn sum_letters(animals: &Vec<&str>) -> usize {
     // pay close attention to the where clause in the function signatures
     // https://doc.rust-lang.org/stable/std/iter/trait.Iterator.html#method.reduce
     // https://doc.rust-lang.org/stable/std/iter/trait.Iterator.html#method.fold
+    // and the return types of the different ways of getting an iterator
+    // https://doc.rust-lang.org/stable/std/iter/
+    // https://doc.rust-lang.org/std/iter/trait.IntoIterator.html#tymethod.into_iter
     // TODO: change the next 2 lines to compile and pass the test.
     let sum_closure = |x: &usize, y: &usize| &(x + y);
     animals.iter().reduce(sum_closure).unwrap().to_owned()
diff --git a/exercises/closures/closures7.rs b/exercises/closures/closures7.rs
index 555aa39c..c0d73b2a 100644
--- a/exercises/closures/closures7.rs
+++ b/exercises/closures/closures7.rs
@@ -20,7 +20,7 @@ fn main() {
     let maybe = Some("yes");
     let list = vec![maybe];
 
-    list.iter().inspect(|&Some(value)| {
+    list.into_iter().inspect(|Some(value)| {
         println!("maybe {:?}", value);
     });
 }
\ No newline at end of file
diff --git a/info.toml b/info.toml
index 6ea0defc..555b2076 100644
--- a/info.toml
+++ b/info.toml
@@ -178,13 +178,15 @@ path = "exercises/closures/closures5.rs"
 mode = "test"
 hint = """
 Getting the signatures of closures right can be tough. I don't think you can write
-any version that fulfills the tests using 'reduce()': you can never return a borrow
+any version that fulfills the tests using 'reduce()' with 'iter()': you can never return a borrow
 of a value owned by a called function.
-You need to replace 'reduce()' with a different function call, update the closure
+You can replace 'reduce()' with a different function call. Update the closure
 so that it matches the signature of this new call, and change the code to return
 the correct type from the sum_letters function. (Using 'sum()' is cheating!)
+OR you can change the sort of iterator you get, so that you don't have to return a reference.
 Pay close attention to the documentation linked to in the exercise: which type
-parameters are the same in the function signatures, and which are different."""
+parameters are the same in the function signatures, and which are different. And
+how do the return types of the variations of getting an iterator differ from each other?"""
 
 [[exercises]]
 name = "closures6"