Added integer addition example

go/cmd/main.go

@@ -7,7 +7,15 @@ package main
 #include "./rustlib.h"
 */
 import "C"
+import "fmt"
 
 func main() {
+	// 1 - Hello
 	C.hello()
+
+	// 2 - Addition
+	x := C.uint32_t(10)
+	y := C.uint32_t(100)
+	add := uint(C.addition(x, y))
+	fmt.Printf("Addition=%d\r\n", add)
 }

go/cmd/rustlib.h

@@ -1 +1,4 @@
-extern int hello();
+#include <stdint.h>
+
+extern void hello();
+extern uint32_t addition(uint32_t, uint32_t);

rust/src/lib.rs

@@ -2,3 +2,8 @@
 pub extern "C" fn hello() {
     println!("Hello World in Rust");
 }
+
+#[no_mangle]
+pub extern "C" fn addition(x: u32, y: u32) -> u32 {
+    x + y
+}