Improve error formatting for WeightedError

src/distributions/weighted_index.rs

@@ -439,15 +439,15 @@ pub enum WeightedError {
 }
 
 #[cfg(feature = "std")]
-impl ::std::error::Error for WeightedError {}
+impl std::error::Error for WeightedError {}
 
 impl fmt::Display for WeightedError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match *self {
-            WeightedError::NoItem => write!(f, "No weights provided."),
-            WeightedError::InvalidWeight => write!(f, "A weight is invalid."),
-            WeightedError::AllWeightsZero => write!(f, "All weights are zero."),
-            WeightedError::TooMany => write!(f, "Too many weights (hit u32::MAX)"),
-        }
+        f.write_str(match *self {
+            WeightedError::NoItem => "No weights provided in distribution",
+            WeightedError::InvalidWeight => "A weight is invalid in distribution",
+            WeightedError::AllWeightsZero => "All weights are zero in distribution",
+            WeightedError::TooMany => "Too many weights (hit u32::MAX) in distribution",
+        })
     }
 }