Closures and Cacher object

[learn-rust.git] / src / main.rs

diff --git a/src/main.rs b/src/main.rs
index 718ecb5f22028762b437c4b87a60dac13f99c90c..0ef1b16f4f9b19c7e9e1c71377abd4273acc0d1b 100644 (file)
--- a/src/main.rs
+++ b/src/main.rs
@@ -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();
 }