Use getrandom crate for uuid

Reduces the number of dependencies.

Cargo.toml

@@ -30,7 +30,7 @@ homepage = "https://github.com/uuid-rs/uuid"
 name = "uuid"
 readme = "README.md"
 repository = "https://github.com/uuid-rs/uuid"
-version = "0.8.1" # remember to update html_root_url in lib.rs
+version = "0.8.2" # remember to update html_root_url in lib.rs
 
 [package.metadata.docs.rs]
 features = [ "guid", "serde", "slog", "v1", "v3", "v4", "v5" ]
@@ -54,6 +54,10 @@ status = "actively-developed"
 [badges.travis-ci]
 repository = "uuid-rs/uuid"
 
+[dependencies.getrandom]
+optional = true
+version = "0.1"
+
 [dependencies.md5]
 optional = true
 version = "0.7"
@@ -95,7 +99,7 @@ std = []
 stdweb = [ "rand/stdweb" ]
 v1 = []
 v3 = ["md5"]
-v4 = ["rand"]
+v4 = ["getrandom"]
 v5 = ["sha1"]
 wasm-bindgen = ["rand/wasm-bindgen"]
 

src/lib.rs

@@ -130,7 +130,7 @@
 #![doc(
     html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
     html_favicon_url = "https://www.rust-lang.org/favicon.ico",
-    html_root_url = "https://docs.rs/uuid/0.8.1"
+    html_root_url = "https://docs.rs/uuid/0.8.2"
 )]
 
 #[cfg(any(feature = "std", test))]

src/v4.rs

@@ -1,5 +1,5 @@
 use crate::prelude::*;
-use rand;
+use getrandom::getrandom;
 
 impl Uuid {
     /// Creates a random UUID.
@@ -23,12 +23,8 @@ impl Uuid {
     ///
     /// [`rand`]: https://crates.io/crates/rand
     pub fn new_v4() -> Self {
-        use rand::RngCore;
-
-        let mut rng = rand::thread_rng();
         let mut bytes = [0; 16];
-
-        rng.fill_bytes(&mut bytes);
+        getrandom(&mut bytes).expect("RNG failure!");
 
         Builder::from_bytes(bytes)
             .set_variant(Variant::RFC4122)