From db9cb70d5d7807adff255e21a04d78c5700d1260 Mon Sep 17 00:00:00 2001
From: William Carroll <wpcarro@gmail.com>
Date: Thu, 1 Sep 2022 09:53:00 -0700
Subject: [PATCH] feat(wpcarro/rust): Define Rc<T> example

My foray into "smart pointer" land.

Change-Id: I4ca775c72168dd34d90bf88fa41149867cd7fdae
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6244
Tested-by: BuildkiteCI
Reviewed-by: wpcarro <wpcarro@gmail.com>
Autosubmit: wpcarro <wpcarro@gmail.com>
---
 users/wpcarro/scratch/rust/shell.nix     |  2 +-
 users/wpcarro/scratch/rust/src/main.rs   |  3 ++-
 users/wpcarro/scratch/rust/src/rc/mod.rs | 12 ++++++++++++
 3 files changed, 15 insertions(+), 2 deletions(-)
 create mode 100644 users/wpcarro/scratch/rust/src/rc/mod.rs

diff --git a/users/wpcarro/scratch/rust/shell.nix b/users/wpcarro/scratch/rust/shell.nix
index 064e7d8bb..98e2dbf4b 100644
--- a/users/wpcarro/scratch/rust/shell.nix
+++ b/users/wpcarro/scratch/rust/shell.nix
@@ -1,4 +1,4 @@
-{ pkgs, ... }:
+{ pkgs ? import <nixpkgs> { }, ... }:
 
 pkgs.mkShell {
   buildInputs = [
diff --git a/users/wpcarro/scratch/rust/src/main.rs b/users/wpcarro/scratch/rust/src/main.rs
index 185e7236c..671b33093 100644
--- a/users/wpcarro/scratch/rust/src/main.rs
+++ b/users/wpcarro/scratch/rust/src/main.rs
@@ -3,6 +3,7 @@ use serde_json::{json, Value};
 
 mod display;
 mod json;
+mod rc;
 mod stdin;
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -10,5 +11,5 @@ mod stdin;
 ////////////////////////////////////////////////////////////////////////////////
 
 fn main() {
-    stdin::example();
+    rc::example();
 }
diff --git a/users/wpcarro/scratch/rust/src/rc/mod.rs b/users/wpcarro/scratch/rust/src/rc/mod.rs
new file mode 100644
index 000000000..67251ca6a
--- /dev/null
+++ b/users/wpcarro/scratch/rust/src/rc/mod.rs
@@ -0,0 +1,12 @@
+// Playing around with Rust's "smart pointers". Starting off with a wrapper type
+// that allows multiple readers (owners?) of some data.
+
+use std::rc::Rc;
+
+pub fn example() {
+    let five = Rc::new(5);
+    let x = Rc::clone(&five);
+    let y = Rc::clone(&five);
+    let z = Rc::clone(&five);
+    println!("result: {}", *x + *y + *z)
+}