Add: Error message in from_slice method.

- Accept owned mapping for `from_mapping`.

crates/circuit/src/circuit_data.rs

@@ -1038,7 +1038,10 @@ impl CircuitData {
     /// Assigns parameters to circuit data based on a slice of `Param`.
     pub fn assign_parameters_from_slice(&mut self, py: Python, slice: &[Param]) -> PyResult<()> {
         if slice.len() != self.param_table.num_parameters() {
-            todo!()
+            return Err(PyValueError::new_err(concat!(
+                "Mismatching number of values and parameters. For partial binding ",
+                "please pass a dictionary of {parameter: value} pairs."
+            )));
         }
         let mut old_table = std::mem::take(&mut self.param_table);
         self.assign_parameters_inner(
@@ -1052,15 +1055,16 @@ impl CircuitData {
     }
 
     /// Assigns parameters to circuit data based on a mapping of `Param` : `Param`.
-    pub fn assign_parameters_from_mapping<'a, I>(&mut self, py: Python, iter: I) -> PyResult<()>
+    /// This mapping assumes that the provided `Param` keys are instances of `ParameterExpression`.
+    pub fn assign_parameters_from_mapping<I>(&mut self, py: Python, iter: I) -> PyResult<()>
     where
-        I: IntoIterator<Item = (&'a Param, &'a Param)>,
+        I: IntoIterator<Item = (Param, Param)>,
     {
         let mut items = Vec::new();
         for (param_obj, value) in iter {
             let param_obj = param_obj.to_object(py);
             let uuid = ParameterUuid::from_parameter(param_obj.bind(py))?;
-            items.push((param_obj, value.clone(), self.param_table.pop(uuid)?));
+            items.push((param_obj, value, self.param_table.pop(uuid)?));
         }
         self.assign_parameters_inner(py, items)
     }