opti(barrier): make new a const fn

Author: librelois

async-barrier/Cargo.toml

@@ -13,7 +13,7 @@ categories = ["asynchronous", "concurrency"]
 readme = "../README.md"
 
 [dependencies]
-async-mutex = "1.1.5"
+async-mutex = { path = "../async-mutex", version = "1.4.0" }
 event-listener = "2.4.0"
 
 [dev-dependencies]

async-barrier/src/lib.rs

@@ -37,7 +37,7 @@ impl Barrier {
     ///
     /// let barrier = Barrier::new(5);
     /// ```
-    pub fn new(n: usize) -> Barrier {
+    pub const fn new(n: usize) -> Barrier {
         Barrier {
             n,
             state: Mutex::new(State {