made bunch of functions const

src/any/difficulty/mod.rs

@@ -30,11 +30,11 @@ pub struct Difficulty<'map> {
 
 impl<'map> Difficulty<'map> {
     /// Create a new difficulty calculator for the given beatmap.
-    pub fn new(map: &'map Beatmap) -> Self {
+    pub const fn new(map: &'map Beatmap) -> Self {
         Self::new_with_is_convert(Cow::Borrowed(map), false)
     }
 
-    fn new_with_is_convert(map: Cow<'map, Beatmap>, is_convert: bool) -> Self {
+    const fn new_with_is_convert(map: Cow<'map, Beatmap>, is_convert: bool) -> Self {
         Self {
             map,
             is_convert,

src/any/difficulty/mode.rs

@@ -14,8 +14,12 @@ pub struct ModeDifficulty {
 
 impl ModeDifficulty {
     /// Create a new difficulty calculator.
-    pub fn new() -> Self {
-        Self::default()
+    pub const fn new() -> Self {
+        Self {
+            mods: 0,
+            passed_objects: None,
+            clock_rate: None,
+        }
     }
 
     /// Specify mods through their bit values.