Use existing code instead of rewriting it

src/lib.rs

@@ -1171,18 +1171,11 @@ pub fn set_max_level(level: LevelFilter) {
 /// [`set_max_level`]: fn.set_max_level.html
 #[inline(always)]
 pub fn max_level() -> LevelFilter {
-    match MAX_LOG_LEVEL_FILTER.load(Ordering::Relaxed) {
-        0 => LevelFilter::Off,
-        1 => LevelFilter::Error,
-        2 => LevelFilter::Warn,
-        3 => LevelFilter::Info,
-        4 => LevelFilter::Debug,
-        5 => LevelFilter::Trace,
-        // Since only this module has access to `MAX_LOG_LEVEL_FILTER`,
-        // and the only time `MAX_LOG_LEVEL_FILTER` is stored to is in `set_max_level`,
-        // the value will always be a valid enum member.
-        _ => unreachable!("only LevelFilter variants are possible"),
-    }
+    let level = MAX_LOG_LEVEL_FILTER.load(Ordering::Relaxed);
+    // Since only this module has access to `MAX_LOG_LEVEL_FILTER`,
+    // and the only time `MAX_LOG_LEVEL_FILTER` is stored to is in `set_max_level`,
+    // the value will always be a valid enum member.
+    LevelFilter::from_usize(level).unwrap()
 }
 
 /// Sets the global logger to a `Box<Log>`.