Insert parentheses as required

Since the fixed expression is used as a receiver for
`.is_power_of_two()`, it may require parentheses.

Author: samueltardieu

clippy_lints/src/manual_is_power_of_two.rs

@@ -69,7 +69,7 @@ fn build_sugg(cx: &LateContext<'_>, expr: &Expr<'_>, receiver: &Expr<'_>) {
         expr.span,
         "manually reimplementing `is_power_of_two`",
         "consider using `.is_power_of_two()`",
-        format!("{snippet}.is_power_of_two()"),
+        format!("{}.is_power_of_two()", snippet.maybe_paren()),
         applicability,
     );
 }

tests/ui/manual_is_power_of_two.fixed

@@ -23,4 +23,8 @@ fn main() {
     // is_power_of_two only works for unsigned integers
     let _ = b.count_ones() == 1;
     let _ = b & (b - 1) == 0;
+
+    let i: i32 = 3;
+    let _ = (i as u32).is_power_of_two();
+    //~^ manual_is_power_of_two
 }

tests/ui/manual_is_power_of_two.rs

@@ -23,4 +23,8 @@ fn main() {
     // is_power_of_two only works for unsigned integers
     let _ = b.count_ones() == 1;
     let _ = b & (b - 1) == 0;
+
+    let i: i32 = 3;
+    let _ = i as u32 & (i as u32 - 1) == 0;
+    //~^ manual_is_power_of_two
 }

tests/ui/manual_is_power_of_two.stderr

@@ -37,5 +37,11 @@ error: manually reimplementing `is_power_of_two`
 LL |     let _ = 0 == (a - 1) & a;
    |             ^^^^^^^^^^^^^^^^ help: consider using `.is_power_of_two()`: `a.is_power_of_two()`
 
-error: aborting due to 6 previous errors
+error: manually reimplementing `is_power_of_two`
+  --> tests/ui/manual_is_power_of_two.rs:28:13
+   |
+LL |     let _ = i as u32 & (i as u32 - 1) == 0;
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `.is_power_of_two()`: `(i as u32).is_power_of_two()`
+
+error: aborting due to 7 previous errors