give std::nullopt default to std::optional

PennyLaneAI · Sep 30, 2024 · 0b943f1 · 0b943f1
1 parent 3047599
commit 0b943f1
Showing 1 changed file with 4 additions and 3 deletions.
diff --git a/pennylane_lightning/core/src/simulators/lightning_qubit/measurements/MeasurementsLQubit.hpp b/pennylane_lightning/core/src/simulators/lightning_qubit/measurements/MeasurementsLQubit.hpp
@@ -23,6 +23,7 @@
 #include <algorithm>
 #include <complex>
 #include <cstdio>
+#include <optional>
 #include <random>
 #include <type_traits>
 #include <unordered_map>
@@ -579,7 +580,7 @@ class Measurements final
      */
     std::vector<std::size_t>
     generate_samples(const std::size_t num_samples,
-                     const std::optional<std::mt19937> &catalyst_rng) {
+                     const std::optional<std::mt19937>& catalyst_rng = std::nullopt) {
         const std::size_t num_qubits = this->_statevector.getNumQubits();
         std::vector<std::size_t> wires(num_qubits);
         std::iota(wires.begin(), wires.end(), 0);
@@ -598,11 +599,11 @@ class Measurements final
     std::vector<std::size_t>
     generate_samples(const std::vector<std::size_t> &wires,
                      const std::size_t num_samples,
-                     const std::optional<std::mt19937> &catalyst_rng) {
+                     const std::optional<std::mt19937>& catalyst_rng = std::nullopt) {
         const std::size_t n_wires = wires.size();
         std::vector<std::size_t> samples(num_samples * n_wires);
         if (catalyst_rng.has_value()) {
-            this->setRNG(catalyst_rng);
+            this->setRNG(catalyst_rng.value());
         } else {
             this->setRandomSeed();
         }