feat: Simplify code by using String::split_ascii_whitespace (#558)

* feat: Simplify code by using `String::split_ascii_whitespace`.

* chore: Update the required version for Rust to 1.34.

Author: Hywan

.github/workflows/main.yml

@@ -91,7 +91,7 @@ jobs:
     steps:
     - uses: actions/checkout@master
     - name: Install Rust
-      run: rustup update 1.31.0 --no-self-update && rustup default 1.31.0
+      run: rustup update 1.34.0 --no-self-update && rustup default 1.34.0
       shell: bash
     - run: cargo build
 

src/lib.rs

@@ -2154,9 +2154,8 @@ impl Build {
     fn envflags(&self, name: &str) -> Vec<String> {
         self.get_var(name)
             .unwrap_or(String::new())
-            .split(|c: char| c.is_whitespace())
-            .filter(|s| !s.is_empty())
-            .map(|s| s.to_string())
+            .split_ascii_whitespace()
+            .map(|slice| slice.to_string())
             .collect()
     }