added more attribute conversions

src/catch/attributes.rs

@@ -87,6 +87,17 @@ impl CatchPerformanceAttributes {
     pub const fn is_convert(&self) -> bool {
         self.difficulty.is_convert
     }
+
+    /// Returns a builder for performance calculation.
+    pub const fn performance<'a>(self) -> CatchPerformance<'a> {
+        CatchPerformance::from_catch_attributes(self.difficulty)
+    }
+}
+
+impl From<CatchPerformanceAttributes> for CatchDifficultyAttributes {
+    fn from(attributes: CatchPerformanceAttributes) -> Self {
+        attributes.difficulty
+    }
 }
 
 #[derive(Clone, Default)]

src/mania/attributes.rs

@@ -79,4 +79,15 @@ impl ManiaPerformanceAttributes {
     pub const fn is_convert(&self) -> bool {
         self.difficulty.is_convert
     }
+
+    /// Returns a builder for performance calculation.
+    pub const fn performance<'a>(self) -> ManiaPerformance<'a> {
+        ManiaPerformance::from_mania_attributes(self.difficulty)
+    }
+}
+
+impl From<ManiaPerformanceAttributes> for ManiaDifficultyAttributes {
+    fn from(attributes: ManiaPerformanceAttributes) -> Self {
+        attributes.difficulty
+    }
 }

src/osu/attributes.rs

@@ -86,4 +86,15 @@ impl OsuPerformanceAttributes {
     pub const fn n_objects(&self) -> u32 {
         self.difficulty.n_objects()
     }
+
+    /// Returns a builder for performance calculation.
+    pub const fn performance<'a>(self) -> OsuPerformance<'a> {
+        OsuPerformance::from_osu_attributes(self.difficulty)
+    }
+}
+
+impl From<OsuPerformanceAttributes> for OsuDifficultyAttributes {
+    fn from(attributes: OsuPerformanceAttributes) -> Self {
+        attributes.difficulty
+    }
 }

src/taiko/attributes.rs

@@ -79,6 +79,11 @@ impl TaikoPerformanceAttributes {
     pub const fn is_convert(&self) -> bool {
         self.difficulty.is_convert
     }
+
+    /// Returns a builder for performance calculation.
+    pub const fn performance<'a>(self) -> TaikoPerformance<'a> {
+        TaikoPerformance::from_taiko_attributes(self.difficulty)
+    }
 }
 
 impl From<TaikoPerformanceAttributes> for TaikoDifficultyAttributes {