X-Git-Url: https://piware.de/gitweb/?p=learn-rust.git;a=blobdiff_plain;f=src%2Fmain.rs;h=3b45c882984a49f2d4303543fba86b80b0f38b53;hp=718ecb5f22028762b437c4b87a60dac13f99c90c;hb=d65f952f600ad2d0828fd650829f6560404dca1c;hpb=f026aa1e762803c4e784f82fd3830c9f936cf8d5

diff --git a/src/main.rs b/src/main.rs
index 718ecb5..3b45c88 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -65,7 +65,7 @@ fn test_hashmaps() {
     println!("scores after doubling: {:?}", scores);
 
     // double scores of immutable hashmap (rebuild it)
-    let collect_scores: HashMap<_, _> = collect_scores.iter()
+    let collect_scores: HashMap<_, _> = collect_scores.into_iter()
         .map(|(k, v)| (k, 2 * v))
         .collect();
     println!("collect_scores after rebuilding with doubling: {:?}", collect_scores);
@@ -137,10 +137,31 @@ fn test_generics() {
     println!("longest string: {}", l);
 }
 
+fn test_closures() {
+    let mut expensive_int_result = Cacher::new(|x| {
+        println!("calculating expensive int result for {}", x);
+        2 * x
+    });
+
+    println!("1st int call for value 1: {}", expensive_int_result.value(1));
+    println!("2nd int call for value 1: {}", expensive_int_result.value(1));
+    println!("1st int call for value 2: {}", expensive_int_result.value(2));
+
+    let mut expensive_str_result = Cacher::new(|x: &str| {
+        println!("calculating expensive str result for {}", x);
+        x.len()
+    });
+
+    println!("1st int call for value abc: {}", expensive_str_result.value("abc"));
+    println!("2nd int call for value abc: {}", expensive_str_result.value("abc"));
+    println!("1st int call for value defg: {}", expensive_str_result.value("defg"));
+}
+
 fn main() {
     test_strings();
     test_vectors();
     test_hashmaps();
     test_files();
     test_generics();
+    test_closures();
 }