added rudimentary display implementation

Author: GueLaKais

rclrs/src/parameter.rs

@@ -643,6 +643,34 @@ pub enum DeclarationError {
     /// An invalid range was provided to a parameter declaration (i.e. lower bound > higher bound).
     InvalidRange,
 }
+impl Display for DeclarationError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            DeclarationError::AlreadyDeclared => write!(
+                f,
+                "Parameter was already declared and a new declaration was attempted"
+            ),
+            DeclarationError::NoValueAvailable => write!(
+                f,
+                "Parameter was declared as non optional but no value was available"
+            ),
+            DeclarationError::OverrideValueTypeMismatch => {
+                write!(f, "The override value that was provided has the wrong type")
+            }
+            DeclarationError::PriorValueTypeMismatch => write!(
+                f,
+                "The value that the parameter was already set to has the wrong type"
+            ),
+            DeclarationError::InitialValueOutOfRange => {
+                write!(f, "The initial value that was selected is out of range")
+            }
+            DeclarationError::InvalidRange => write!(
+                f,
+                "An invalid range was provided to a parameter declaration"
+            ),
+        }
+    }
+}
 
 impl<'a> Parameters<'a> {
     /// Tries to read a parameter of the requested type.