Add flake dev shell

Author: zetanumbers

.envrc

@@ -0,0 +1 @@
+use flake

.gitignore

@@ -1 +1,2 @@
 /target
+/.direnv

Cargo.toml

@@ -1,13 +1,13 @@
 [package]
 name = "scope-lock"
 version = "0.2.5"
-edition = "2021"
+edition = "2024"
 # TODO: elaborate
 description = "Safely extend lifetimes"
 # TODO: Apache 2.0
 license = "MIT"
 repository = "https://github.com/zetanumbers/scope-lock"
-rust-version = "1.66"
+rust-version = "1.85"
 
 [dependencies]
 parking_lot = { version = "0.12.2", features = ["send_guard"] }

flake.lock

@@ -0,0 +1,29 @@
+{
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+    rust-overlay = {
+      url = "github:oxalica/rust-overlay";
+      inputs = {
+        nixpkgs.follows = "nixpkgs";
+      };
+    };
+  };
+  outputs = { self, nixpkgs, flake-utils, rust-overlay }:
+    flake-utils.lib.eachDefaultSystem
+      (system:
+        let
+          overlays = [ (import rust-overlay) ];
+          pkgs = import nixpkgs {
+            inherit system overlays;
+          };
+          rustToolchain = pkgs.pkgsBuildHost.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
+        in
+        with pkgs;
+        {
+          devShells.default = mkShell {
+            buildInputs = [rustToolchain];
+          };
+        }
+      );
+}

flake.nix

@@ -0,0 +1,4 @@
+[toolchain]
+channel = "1.85"
+components = ["rust-analyzer", "rust-src"]
+