cargo: add module

modules/programs/cargo.nix

@@ -0,0 +1,43 @@
+{
+  lib,
+  config,
+  pkgs,
+  ...
+}:
+let
+  inherit (lib) mkEnableOption;
+
+  tomlFormat = pkgs.formats.toml { };
+
+  cfg = config.programs.cargo;
+in
+{
+  meta.maintainers = [ lib.maintainers.friedrichaltheide ];
+
+  options = {
+    programs = {
+      cargo = {
+        enable = mkEnableOption "management of cargo config";
+
+        settings = lib.mkOption {
+          inherit (tomlFormat) type;
+          default = { };
+          description = ''
+            Available configuration options for the .cargo/config see:
+            https://doc.rust-lang.org/cargo/reference/config.html
+          '';
+        };
+      };
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    home = {
+      file = {
+        ".cargo/config.toml" = {
+          source = tomlFormat.generate "config.toml" cfg.settings;
+        };
+      };
+    };
+  };
+}