clippy: replace vector indexing with safe .get() method

Author: sylvestre

src/uu/df/src/table.rs

@@ -447,16 +447,19 @@ impl fmt::Display for Table {
             while let Some((i, elem)) = col_iter.next() {
                 let is_last_col = col_iter.peek().is_none();
 
-                match self.alignments[i] {
-                    Alignment::Left => {
+                match self.alignments.get(i) {
+                    Some(Alignment::Left) => {
                         if is_last_col {
                             // no trailing spaces in last column
                             write!(f, "{elem}")?;
                         } else {
                             write!(f, "{:<width$}", elem, width = self.widths[i])?;
                         }
                     }
-                    Alignment::Right => write!(f, "{:>width$}", elem, width = self.widths[i])?,
+                    Some(Alignment::Right) => {
+                        write!(f, "{:>width$}", elem, width = self.widths[i])?;
+                    }
+                    None => break,
                 }
 
                 if !is_last_col {

src/uu/expand/src/expand.rs

@@ -381,10 +381,10 @@ fn expand_line(
             }
         } else {
             (
-                match buf[byte] {
+                match buf.get(byte) {
                     // always take exactly 1 byte in strict ASCII mode
-                    0x09 => Tab,
-                    0x08 => Backspace,
+                    Some(0x09) => Tab,
+                    Some(0x08) => Backspace,
                     _ => Other,
                 },
                 1,

src/uu/stat/src/stat.rs

@@ -755,11 +755,11 @@ impl Stater {
         let chars = format_str.chars().collect::<Vec<char>>();
         let mut i = 0;
         while i < bound {
-            match chars[i] {
-                '%' => tokens.push(Self::handle_percent_case(
+            match chars.get(i) {
+                Some('%') => tokens.push(Self::handle_percent_case(
                     &chars, &mut i, bound, format_str,
                 )?),
-                '\\' => {
+                Some('\\') => {
                     if use_printf {
                         tokens.push(Self::handle_escape_sequences(
                             &chars, &mut i, bound, format_str,
@@ -768,7 +768,8 @@ impl Stater {
                         tokens.push(Token::Char('\\'));
                     }
                 }
-                c => tokens.push(Token::Char(c)),
+                Some(c) => tokens.push(Token::Char(*c)),
+                None => break,
             }
             i += 1;
         }