refactor

src/ui/color.rs

@@ -1,10 +1,14 @@
 /// UI Color
 pub trait UIColor {
+    #[must_use]
     fn color_class(&self) -> &str;
 }
 
 pub trait ColorCircle {
+    #[must_use]
     fn previous(&self) -> Self;
+
+    #[must_use]
     fn next(&self) -> Self;
 }
 
@@ -119,11 +123,11 @@ pub enum Colors {
 impl UIColor for Colors {
     fn color_class(&self) -> &str {
         match self {
-            Colors::Inherit => "inherit",
-            Colors::Current => "current",
-            Colors::Transparent => "transparent",
-            Colors::Black => "black",
-            Colors::White => "white",
+            Self::Inherit => "inherit",
+            Self::Current => "current",
+            Self::Transparent => "transparent",
+            Self::Black => "black",
+            Self::White => "white",
         }
     }
 }