Deduplicate SliceOrInt (#11844)

* Deduplicate SliceOrInt

After doing some post-merge analysis on the impact of #11842 it turns
out the enum being modified in that PR was duplicated in the rust code
unnecessarily. The same enum was already defined in the
euler_one_qubit_decomposer module for it's custom 1 qubit gate sequence
return type. This commit updates the code so it just use the one
defined in the circuit data module that has the fix from #11842 applied
already.

* Move enum to common location

crates/accelerate/src/euler_one_qubit_decomposer.rs

@@ -19,20 +19,15 @@ use std::f64::consts::PI;
 
 use pyo3::exceptions::{PyIndexError, PyTypeError};
 use pyo3::prelude::*;
-use pyo3::types::PySlice;
 use pyo3::wrap_pyfunction;
 use pyo3::Python;
 
 use ndarray::prelude::*;
 use numpy::PyReadonlyArray2;
 
-const DEFAULT_ATOL: f64 = 1e-12;
+use crate::utils::SliceOrInt;
 
-#[derive(FromPyObject)]
-enum SliceOrInt<'a> {
-    Slice(&'a PySlice),
-    Int(isize),
-}
+const DEFAULT_ATOL: f64 = 1e-12;
 
 #[pyclass(module = "qiskit._accelerate.euler_one_qubit_decomposer")]
 pub struct OneQubitGateErrorMap {

crates/accelerate/src/quantum_circuit/circuit_data.rs

@@ -13,6 +13,7 @@
 use crate::quantum_circuit::circuit_instruction::CircuitInstruction;
 use crate::quantum_circuit::intern_context::{BitType, IndexType, InternContext};
 use crate::quantum_circuit::py_ext;
+use crate::utils::SliceOrInt;
 use hashbrown::HashMap;
 use pyo3::exceptions::{PyIndexError, PyKeyError, PyRuntimeError, PyValueError};
 use pyo3::prelude::*;
@@ -153,16 +154,6 @@ pub struct CircuitData {
     clbits: Py<PyList>,
 }
 
-/// A private enumeration type used to extract arguments to pymethods
-/// that may be either an index or a slice.
-#[derive(FromPyObject)]
-pub enum SliceOrInt<'a> {
-    // The order here defines the order the variants are tried in the `FromPyObject` derivation.
-    // `Int` is _much_ more common, so that should be first.
-    Int(isize),
-    Slice(&'a PySlice),
-}
-
 #[pymethods]
 impl CircuitData {
     #[new]

crates/accelerate/src/utils.rs

@@ -11,12 +11,23 @@
 // that they have been altered from the originals.
 
 use pyo3::prelude::*;
+use pyo3::types::PySlice;
 
 use faer::prelude::*;
 use faer::IntoFaerComplex;
 use num_complex::Complex;
 use numpy::{IntoPyArray, PyReadonlyArray2};
 
+/// A private enumeration type used to extract arguments to pymethod
+/// that may be either an index or a slice
+#[derive(FromPyObject)]
+pub enum SliceOrInt<'a> {
+    // The order here defines the order the variants are tried in the FromPyObject` derivation.
+    // `Int` is _much_ more common, so that should be first.
+    Int(isize),
+    Slice(&'a PySlice),
+}
+
 /// Return indices that sort partially ordered data.
 /// If `data` contains two elements that are incomparable,
 /// an error will be thrown.