add xmtp_xid crate

Cargo.toml

@@ -8,7 +8,7 @@ members = [
   "xmtp_proto",
   "xmtp_user_preferences",
   "xmtp_v2",
-  "xmtp_mls", "xps-client",
+  "xmtp_mls", "xps-client", "xmtp_xid",
 ]
 
 exclude = [

xmtp_xid/Cargo.toml

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

xmtp_xid/src/lib.rs

@@ -0,0 +1,14 @@
+pub fn add(left: usize, right: usize) -> usize {
+    left + right
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn it_works() {
+        let result = add(2, 2);
+        assert_eq!(result, 4);
+    }
+}