第一个版本

.gitignore

@@ -0,0 +1,11 @@
+/target
+**/*.rs.bk
+
+
+#Added by cargo
+#
+#already existing elements are commented out
+
+#/target
+#**/*.rs.bk
+Cargo.lock

Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "add"
+version = "0.1.0"
+authors = ["llgoer <llgoer@github.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

src/lib.rs

@@ -0,0 +1,22 @@
+// Copyright 2019 GoKeep Author. All rights reserved.
+// license that can be found in the LICENSE file.
+
+pub fn add(a: i32, b: i32) -> i32 {
+    a + b
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    
+    #[test]
+    fn test_add() {
+        assert_eq!(add(1, 2), 3);
+    }
+
+
+    #[test]
+    fn it_works() {
+        assert_eq!(2 + 2, 4);
+    }
+}