Add a precision enum to kraus_op to track the underlying data type (#2551)

* Add precision enum to kraus_op to track the underlying data type

Signed-off-by: Thien Nguyen <[email protected]>

* Update downstream commit hash incorporating this change

Signed-off-by: Thien Nguyen <[email protected]>

* Fix docs build: cudaq::real is Doxygen'ed but cudaq::complex::value_type is not

Signed-off-by: Thien Nguyen <[email protected]>

---------

Signed-off-by: Thien Nguyen <[email protected]>

Author: 1tnguyen

.github/workflows/config/gitlab_commits.txt

@@ -1,2 +1,2 @@
 nvidia-mgpu-repo: cuda-quantum/cuquantum-mgpu.git
-nvidia-mgpu-commit: fdea89e034c7ac6b6b3d0e239d8924bcd2c08f96
+nvidia-mgpu-commit: 02cb381cb54b0c11de8b8aaa75ccff2fdd0a2e0d

runtime/common/NoiseModel.h

@@ -46,6 +46,14 @@ struct kraus_op {
   /// NOTE we currently assume nRows == nCols
   std::size_t nCols = 0;
 
+  /// @brief The precision of the underlying data
+  // This data is populated when a `kraus_op` is created and can be used to
+  // introspect `kraus_op` objects across library boundary (e.g., when dynamic
+  // linking is involved).
+  const cudaq::simulation_precision precision =
+      std::is_same_v<cudaq::real, float> ? cudaq::simulation_precision::fp32
+                                         : cudaq::simulation_precision::fp64;
+
   /// @brief Copy constructor
   kraus_op(const kraus_op &) = default;