add: lazy_static device ref

Cargo.lock

@@ -35,6 +35,7 @@ name = "dpk"
 version = "0.1.0"
 dependencies = [
  "evdev",
+ "lazy_static",
 ]
 
 [[package]]
@@ -54,6 +55,12 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1847abb9cb65d566acd5942e94aea9c8f547ad02c98e1649326fc0e8910b8b1e"
 
+[[package]]
+name = "lazy_static"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+
 [[package]]
 name = "libc"
 version = "0.2.97"

Cargo.toml

@@ -7,4 +7,5 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-evdev = "0.11.0"
+evdev = "0.11.0"
+lazy_static = "1.4.0"

src/main.rs

@@ -1,10 +1,17 @@
 use std::{io::Write, thread::sleep};
+#[macro_use]
+extern crate lazy_static;
 
 fn main() -> ! {
-    let d = pick_device();
-    println!("{}", d.name().unwrap_or("Unknown device"));
+    lazy_static! {
+        static ref D: evdev::Device = {
+            let d = pick_device();
+            d
+        };
+    }
+    println!("{}", D.name().unwrap_or("Unknown device"));
     loop {
-        if d.get_key_state().unwrap().contains(evdev::Key::BTN_SIDE) {
+        if D.get_key_state().unwrap().contains(evdev::Key::BTN_SIDE) {
             println!("BTN_SIDE");
         }
         std::thread::sleep(std::time::Duration::from_millis(100));