Support macros being used in a module with #[deny(unsafe_code)]

Author: SimonSapin

src/lib.rs

@@ -226,14 +226,14 @@ macro_rules! _cssparser_internal__to_lowercase {
         #[allow(dead_code)]
         struct Dummy2;
 
-        // MAX_LENGTH is generated by cssparser__match_ignore_ascii_case__max_len
-        let mut buffer: [u8; MAX_LENGTH] =
-            // `buffer` is only used in `_internal__to_lowercase`,
-            // which initializes with `copy_from_slice` the part of the buffer it uses,
-            // before it uses it.
-            unsafe {
-                ::std::mem::uninitialized()
-            };
+        // mem::uninitialized() is ok because `buffer` is only used in `_internal__to_lowercase`,
+        // which initializes with `copy_from_slice` the part of the buffer it uses,
+        // before it uses it.
+        #[allow(unsafe_code)]
+        // MAX_LENGTH is generated by cssparser__max_len
+        let mut buffer: [u8; MAX_LENGTH] = unsafe {
+            ::std::mem::uninitialized()
+        };
         let $output = $crate::_internal__to_lowercase(&mut buffer, $input);
     }
 }