Initial commit.

func_pointer/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "func_pointer"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

func_pointer/src/main.rs

@@ -0,0 +1,30 @@
+fn add_one(x: i32) -> i32 {
+    x + 1
+}
+
+fn do_twice(f: fn(i32) -> i32, arg: i32) -> i32 {
+    f(arg) + f(arg)
+}
+
+
+fn main() {
+    let answer = do_twice(add_one, 5);
+
+    println! ("答案为：{}", answer);
+
+    let list_of_numbers = vec! [1, 2, 3];
+    let list_of_strings: Vec<String> =
+        list_of_numbers.iter().map(ToString::to_string).collect();
+
+    println! ("结果为：{:?}", list_of_strings);
+
+    #[derive(Debug)]
+    enum Status {
+        Value(u32),
+        Stop,
+    }
+
+    let mut list_of_statuses: Vec<Status> = (0u32..20).map(Status::Value).collect();
+    list_of_statuses.append(&mut vec! [Status::Stop]);
+    println! ("list_of_statuses: {:?}", list_of_statuses);
+}