Use str::repeat

Author: sinkuu

src/config/config_type.rs

@@ -236,10 +236,7 @@ macro_rules! create_config {
                 use std::cmp;
                 let max = 0;
                 $( let max = cmp::max(max, stringify!($i).len()+1); )+
-                let mut space_str = String::with_capacity(max);
-                for _ in 0..max {
-                    space_str.push(' ');
-                }
+                let space_str = " ".repeat(max);
                 writeln!(out, "Configuration Options:").unwrap();
                 $(
                     if $stb || include_unstable {

src/macros.rs

@@ -540,17 +540,12 @@ fn register_metavariable(
     name: &str,
     dollar_count: usize,
 ) {
-    let mut new_name = String::new();
-    let mut old_name = String::new();
+    let mut new_name = "$".repeat(dollar_count - 1);
+    let mut old_name = "$".repeat(dollar_count);
 
-    old_name.push('$');
-    for _ in 0..(dollar_count - 1) {
-        new_name.push('$');
-        old_name.push('$');
-    }
     new_name.push('z');
-    new_name.push_str(&name);
-    old_name.push_str(&name);
+    new_name.push_str(name);
+    old_name.push_str(name);
 
     result.push_str(&new_name);
     map.insert(old_name, new_name);