Move Option<Box<_>> into ExtraInstructionAttributes.

Previously, CircuitInstruction and PackedInstruction held
the ExtraInstructionAttributes struct within an Option<Box<_>>.
By putting the Option<Box<_>> inside ExtraInstructionAttributes,
we can use the struct itself to manage its memory and provide
access to the attributes behind a nicer interface.

The size of ExtraInstructionAttributes should be the same size
as the old Option<Box<ExtraInstructionAttributes>>, so this
should not have memory implications.

crates/accelerate/src/commutation_analysis.rs

@@ -95,12 +95,12 @@ fn analyze_commutations_inner(
                             py,
                             &op1,
                             params1,
-                            packed_inst0.extra_attrs.as_deref(),
+                            &packed_inst0.extra_attrs,
                             qargs1,
                             cargs1,
                             &op2,
                             params2,
-                            packed_inst1.extra_attrs.as_deref(),
+                            &packed_inst1.extra_attrs,
                             qargs2,
                             cargs2,
                             MAX_NUM_QUBITS,

crates/accelerate/src/commutation_checker.rs

@@ -121,12 +121,12 @@ impl CommutationChecker {
             py,
             &op1.instruction.operation.view(),
             &op1.instruction.params,
-            op1.instruction.extra_attrs.as_deref(),
+            &op1.instruction.extra_attrs,
             &qargs1,
             &cargs1,
             &op2.instruction.operation.view(),
             &op2.instruction.params,
-            op2.instruction.extra_attrs.as_deref(),
+            &op2.instruction.extra_attrs,
             &qargs2,
             &cargs2,
             max_num_qubits,
@@ -162,12 +162,12 @@ impl CommutationChecker {
             py,
             &op1.operation.view(),
             &op1.params,
-            op1.extra_attrs.as_deref(),
+            &op1.extra_attrs,
             &qargs1,
             &cargs1,
             &op2.operation.view(),
             &op2.params,
-            op2.extra_attrs.as_deref(),
+            &op2.extra_attrs,
             &qargs2,
             &cargs2,
             max_num_qubits,
@@ -232,12 +232,12 @@ impl CommutationChecker {
         py: Python,
         op1: &OperationRef,
         params1: &[Param],
-        attrs1: Option<&ExtraInstructionAttributes>,
+        attrs1: &ExtraInstructionAttributes,
         qargs1: &[Qubit],
         cargs1: &[Clbit],
         op2: &OperationRef,
         params2: &[Param],
-        attrs2: Option<&ExtraInstructionAttributes>,
+        attrs2: &ExtraInstructionAttributes,
         qargs2: &[Qubit],
         cargs2: &[Clbit],
         max_num_qubits: u32,
@@ -494,20 +494,20 @@ impl CommutationChecker {
 fn commutation_precheck(
     op1: &OperationRef,
     params1: &[Param],
-    attrs1: Option<&ExtraInstructionAttributes>,
+    attrs1: &ExtraInstructionAttributes,
     qargs1: &[Qubit],
     cargs1: &[Clbit],
     op2: &OperationRef,
     params2: &[Param],
-    attrs2: Option<&ExtraInstructionAttributes>,
+    attrs2: &ExtraInstructionAttributes,
     qargs2: &[Qubit],
     cargs2: &[Clbit],
     max_num_qubits: u32,
 ) -> Option<bool> {
     if op1.control_flow()
         || op2.control_flow()
-        || attrs1.is_some_and(|attr| attr.condition.is_some())
-        || attrs2.is_some_and(|attr| attr.condition.is_some())
+        || attrs1.condition().is_some()
+        || attrs2.condition().is_some()
     {
         return Some(false);
     }

crates/circuit/src/circuit_data.rs

@@ -14,7 +14,9 @@
 use std::cell::OnceCell;
 
 use crate::bit_data::BitData;
-use crate::circuit_instruction::{CircuitInstruction, OperationFromPython};
+use crate::circuit_instruction::{
+    CircuitInstruction, ExtraInstructionAttributes, OperationFromPython,
+};
 use crate::imports::{ANNOTATED_OPERATION, CLBIT, QUANTUM_CIRCUIT, QUBIT};
 use crate::interner::{Interned, Interner};
 use crate::operations::{Operation, OperationRef, Param, StandardGate};
@@ -157,7 +159,7 @@ impl CircuitData {
                 qubits,
                 clbits,
                 params,
-                extra_attrs: None,
+                extra_attrs: ExtraInstructionAttributes::default(),
                 #[cfg(feature = "cache_pygates")]
                 py_op: OnceCell::new(),
             });
@@ -209,7 +211,7 @@ impl CircuitData {
                 qubits,
                 clbits: no_clbit_index,
                 params,
-                extra_attrs: None,
+                extra_attrs: ExtraInstructionAttributes::default(),
                 #[cfg(feature = "cache_pygates")]
                 py_op: OnceCell::new(),
             });
@@ -267,7 +269,7 @@ impl CircuitData {
             qubits,
             clbits: no_clbit_index,
             params,
-            extra_attrs: None,
+            extra_attrs: ExtraInstructionAttributes::default(),
             #[cfg(feature = "cache_pygates")]
             py_op: OnceCell::new(),
         });
@@ -626,12 +628,7 @@ impl CircuitData {
     #[pyo3(signature = (func))]
     pub fn map_nonstandard_ops(&mut self, py: Python<'_>, func: &Bound<PyAny>) -> PyResult<()> {
         for inst in self.data.iter_mut() {
-            if inst.op.try_standard_gate().is_some()
-                && !inst
-                    .extra_attrs
-                    .as_ref()
-                    .is_some_and(|attrs| attrs.condition.is_some())
-            {
+            if inst.op.try_standard_gate().is_some() && inst.extra_attrs.condition().is_none() {
                 continue;
             }
             let py_op = func.call1((inst.unpack_py_op(py)?,))?;