new nix draft

Signed-off-by: Ruowen Qin <chinqrw@gmail.com>

Author: chinrw

tools/memcached_benchmark/Cargo.toml

@@ -38,3 +38,4 @@ debug = false
 codegen-units = 1
 panic = "abort"
 strip = true
+lto = "thin"

tools/memcached_benchmark/flake.lock

@@ -0,0 +1,47 @@
+{
+  description = "Rust development environment";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    rust-overlay.url = "github:oxalica/rust-overlay";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, rust-overlay, flake-utils, ... }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        overlays = [ (import rust-overlay) ];
+        pkgs = import nixpkgs {
+          inherit system overlays;
+        };
+
+        # 1. Replicate languages.rust
+        rustToolchain = pkgs.rust-bin.nightly.latest.default.override {
+          extensions = [
+            "rust-src"
+            "rustc"
+            "clippy"
+            "rust-analyzer"
+            "rustfmt"
+          ];
+        };
+      in
+      {
+        devShells.default = pkgs.mkShell {
+          buildInputs = with pkgs; [
+            git
+            mold
+            llvmPackages.clangUseLLVM
+            memcached
+            rustToolchain
+          ];
+
+          shellHook = ''
+            # enterShell logic
+            clang --version
+            rustc --version
+          '';
+        };
+      }
+    );
+}