Update to Rust 1.75, fix new clippy lints (#147)

* Update Rust toolchain version

* Fix new clippy lints

* Fix formatting

backend/src/lib.rs

@@ -612,6 +612,8 @@ pub extern "C" fn __quantum__qis__reset__body(qubit: *mut c_void) {
 
 /// QIR API for measuring the given qubit and storing the measured value with the given result identifier,
 /// then resetting it in the computational basis.
+#[allow(clippy::missing_panics_doc)]
+// reason="Panics can only occur if the result that was just collected is not found in the BitVec, which should not happen."
 #[no_mangle]
 pub extern "C" fn __quantum__qis__mresetz__body(qubit: *mut c_void, result: *mut c_void) {
     SIM_STATE.with(|sim_state| {
@@ -637,6 +639,8 @@ pub extern "C" fn __quantum__qis__mresetz__body(qubit: *mut c_void, result: *mut
 }
 
 /// QIR API for measuring the given qubit in the computation basis and storing the measured value with the given result identifier.
+#[allow(clippy::missing_panics_doc)]
+// reason="Panics can only occur if the result index is not found in the BitVec after resizing, which should not happen."
 #[no_mangle]
 pub extern "C" fn __quantum__qis__mz__body(qubit: *mut c_void, result: *mut c_void) {
     SIM_STATE.with(|sim_state| {
@@ -658,6 +662,8 @@ pub extern "C" fn __quantum__qis__mz__body(qubit: *mut c_void, result: *mut c_vo
 
 /// QIR API that reads the Boolean value corresponding to the given result identifier, where true
 /// indicates a |1⟩ state and false indicates a |0⟩ state.
+#[allow(clippy::missing_panics_doc)]
+// reason="Panics can only occur if the result index is not found in the BitVec after resizing, which should not happen."
 #[no_mangle]
 pub extern "C" fn __quantum__qis__read_result__body(result: *mut c_void) -> bool {
     SIM_STATE.with(|sim_state| {
@@ -813,6 +819,8 @@ pub mod legacy_output {
         SIM_STATE,
     };
 
+    #[allow(clippy::missing_panics_doc)]
+    // reason="Panics can only occur if the result index is not found in the BitVec after resizing, which should not happen."
     #[allow(non_snake_case)]
     pub extern "C" fn __quantum__rt__result_record_output(result: *mut c_void) {
         SIM_STATE.with(|sim_state| {
@@ -835,6 +843,8 @@ pub mod legacy_output {
 }
 
 /// QIR API for recording the given result into the program output.
+#[allow(clippy::missing_panics_doc)]
+// reason="Panics can only occur if the result index is not found in the BitVec after resizing, which should not happen."
 #[no_mangle]
 pub extern "C" fn __quantum__rt__result_record_output(result: *mut c_void, tag: *mut c_char) {
     SIM_STATE.with(|sim_state| {
@@ -894,6 +904,8 @@ pub extern "C" fn __quantum__rt__qubit_allocate() -> *mut c_void {
 }
 
 /// QIR API for allocating the given number of qubits in the simulation, returning them as a runtime managed array.
+/// # Panics
+/// This function will panic if the requested array size is too large to be described with the system pointer size.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
 pub extern "C" fn __quantum__rt__qubit_allocate_array(size: u64) -> *const QirArray {
@@ -936,6 +948,8 @@ pub extern "C" fn __quantum__rt__qubit_release(qubit: *mut c_void) {
 }
 
 /// QIR API for getting the string interpretation of a qubit identifier.
+/// # Panics
+/// This function will panic if memory cannot be allocated for the underyling string.
 #[no_mangle]
 pub extern "C" fn __quantum__rt__qubit_to_string(qubit: *mut c_void) -> *const CString {
     unsafe {

backend/src/result_bool.rs

@@ -25,6 +25,8 @@ pub extern "C" fn __quantum__rt__result_update_reference_count(_res: *mut c_void
     // no-op
 }
 
+/// # Panics
+/// This function panics if the memory cannot be allocated for the result string.
 #[no_mangle]
 pub extern "C" fn __quantum__rt__result_to_string(res: *mut c_void) -> *const CString {
     unsafe {

rust-toolchain.toml

@@ -1,3 +1,3 @@
 [toolchain]
-channel = "1.70"
+channel = "1.75"
 components = [ "rustfmt", "clippy", "llvm-tools-preview" ]

sparsesim/src/lib.rs

@@ -88,6 +88,7 @@ impl QuantumSim {
 
     /// Returns a sorted copy of the current sparse state as a vector of pairs of indices and complex numbers, along with
     /// the total number of currently allocated qubits to help in interpreting the sparse state.
+    #[allow(clippy::missing_panics_doc)] // reason="Panics can only occur if the keys are not present in the map, which should not happen."
     #[must_use]
     pub fn get_state(&mut self) -> (Vec<(BigUint, Complex64)>, usize) {
         // Swap all the entries in the state to be ordered by qubit identifier. This makes
@@ -188,6 +189,7 @@ impl QuantumSim {
 
     /// Prints the current state vector to standard output with integer labels for the states, skipping any
     /// states with zero amplitude.
+    #[allow(clippy::missing_panics_doc)] // reason="Panics can only occur if the keys are not present in the map, which should not happen."
     pub fn dump(&mut self) {
         // Swap all the entries in the state to be ordered by qubit identifier. This makes
         // interpreting the state easier for external consumers that don't have access to the id map.
@@ -446,7 +448,7 @@ impl QuantumSim {
 
     pub(crate) fn check_for_duplicates(ids: &[usize]) {
         let mut unique = FxHashSet::default();
-        for id in ids.iter() {
+        for id in ids {
             assert!(
                 unique.insert(id),
                 "Duplicate qubit id '{id}' found in application."
@@ -617,6 +619,7 @@ impl QuantumSim {
     }
 
     /// Multi-controlled Y gate.
+    #[allow(clippy::missing_panics_doc)] // reason="Panics can only occur if ctrls are empty, which is handled at the top of the function."
     pub fn mcy(&mut self, ctls: &[usize], target: usize) {
         if ctls.is_empty() {
             self.y(target);

stdlib/src/arrays.rs

@@ -69,8 +69,7 @@ pub unsafe extern "C" fn __quantum__rt__array_concatenate(
     new_array.data.resize(array1.data.len(), 0_u8);
     new_array.data.copy_from_slice(array1.data.as_slice());
 
-    let mut copy = Vec::new();
-    copy.resize(array2.data.len(), 0_u8);
+    let mut copy = vec![0; array2.data.len()];
     copy.copy_from_slice(array2.data.as_slice());
 
     new_array.data.append(&mut copy);

stdlib/src/bigints.rs

@@ -172,7 +172,7 @@ mod tests {
     fn test_bigint_create_from_int() {
         let bigint_0 = __quantum__rt__bigint_create_i64(42);
         unsafe {
-            assert_eq!(*bigint_0, (42).try_into().unwrap());
+            assert_eq!(*bigint_0, (42).into());
             // Note that the test must decrement the reference count on any created items to ensure
             // they are cleaned up and tests can pass with address sanitizer.
             __quantum__rt__bigint_update_reference_count(bigint_0, -1);
@@ -185,10 +185,7 @@ mod tests {
         unsafe {
             let bigint_1 =
                 __quantum__rt__bigint_create_array(bytes.len().try_into().unwrap(), bytes.as_ptr());
-            assert_eq!(
-                *bigint_1,
-                (9_223_372_036_854_775_807_i64).try_into().unwrap()
-            );
+            assert_eq!(*bigint_1, (9_223_372_036_854_775_807_i64).into());
             __quantum__rt__bigint_update_reference_count(bigint_1, -1);
         }
     }
@@ -199,19 +196,19 @@ mod tests {
         let bigint_1 = __quantum__rt__bigint_create_i64(3);
         unsafe {
             let bigint_2 = __quantum__rt__bigint_add(bigint_0, bigint_1);
-            assert_eq!(*bigint_2, (45).try_into().unwrap());
+            assert_eq!(*bigint_2, (45).into());
             let bigint_3 = __quantum__rt__bigint_subtract(bigint_2, bigint_1);
-            assert_eq!(*bigint_3, (42).try_into().unwrap());
+            assert_eq!(*bigint_3, (42).into());
             let bigint_4 = __quantum__rt__bigint_divide(bigint_3, bigint_1);
-            assert_eq!(*bigint_4, (14).try_into().unwrap());
+            assert_eq!(*bigint_4, (14).into());
             let bigint_5 = __quantum__rt__bigint_multiply(bigint_4, bigint_1);
-            assert_eq!(*bigint_5, (42).try_into().unwrap());
+            assert_eq!(*bigint_5, (42).into());
             let bigint_6 = __quantum__rt__bigint_modulus(bigint_5, bigint_1);
-            assert_eq!(*bigint_6, (0).try_into().unwrap());
+            assert_eq!(*bigint_6, (0).into());
             let bigint_7 = __quantum__rt__bigint_negate(bigint_5);
-            assert_eq!(*bigint_7, (-42).try_into().unwrap());
+            assert_eq!(*bigint_7, (-42).into());
             let bigint_8 = __quantum__rt__bigint_power(bigint_7, 3);
-            assert_eq!(*bigint_8, (-74088).try_into().unwrap());
+            assert_eq!(*bigint_8, (-74088).into());
             __quantum__rt__bigint_update_reference_count(bigint_8, -1);
             __quantum__rt__bigint_update_reference_count(bigint_7, -1);
             __quantum__rt__bigint_update_reference_count(bigint_6, -1);
@@ -230,17 +227,17 @@ mod tests {
         let bigint_1 = __quantum__rt__bigint_create_i64(3);
         unsafe {
             let bigint_2 = __quantum__rt__bigint_bitand(bigint_0, bigint_1);
-            assert_eq!(*bigint_2, (2).try_into().unwrap());
+            assert_eq!(*bigint_2, (2).into());
             let bigint_3 = __quantum__rt__bigint_bitor(bigint_0, bigint_1);
-            assert_eq!(*bigint_3, (43).try_into().unwrap());
+            assert_eq!(*bigint_3, (43).into());
             let bigint_4 = __quantum__rt__bigint_bitxor(bigint_0, bigint_3);
-            assert_eq!(*bigint_4, (1).try_into().unwrap());
+            assert_eq!(*bigint_4, (1).into());
             let bigint_5 = __quantum__rt__bigint_bitnot(bigint_4);
-            assert_eq!(*bigint_5, (-2).try_into().unwrap());
+            assert_eq!(*bigint_5, (-2).into());
             let bigint_6 = __quantum__rt__bigint_shiftleft(bigint_0, 2);
-            assert_eq!(*bigint_6, (168).try_into().unwrap());
+            assert_eq!(*bigint_6, (168).into());
             let bigint_7 = __quantum__rt__bigint_shiftright(bigint_6, 3);
-            assert_eq!(*bigint_7, (21).try_into().unwrap());
+            assert_eq!(*bigint_7, (21).into());
             __quantum__rt__bigint_update_reference_count(bigint_7, -1);
             __quantum__rt__bigint_update_reference_count(bigint_6, -1);
             __quantum__rt__bigint_update_reference_count(bigint_5, -1);

stdlib/src/range_support.rs

@@ -51,8 +51,7 @@ pub unsafe extern "C" fn quantum__rt__array_slice_1d(
         let index = i
             .try_into()
             .expect("Item index too large for `usize` type on this platform.");
-        let mut copy = Vec::new();
-        copy.resize(array.elem_size, 0_u8);
+        let mut copy = vec![0; array.elem_size];
         copy.copy_from_slice(&array.data[index..index + array.elem_size]);
         slice.data.append(&mut copy);
     }