Update the unification work required for the external package development

.github/CHANGELOG.md

@@ -21,6 +21,10 @@
 * Add memory locality tag reporting and adjoint diff dispatch for `lightning.qubit` statevector classes.
   [(#492)](https://github.com/PennyLaneAI/pennylane-lightning/pull/492)
 
+* Add support for dependent external packages to C++ core.
+  [(#482)](https://github.com/PennyLaneAI/pennylane-lightning/pull/482)
+
+
 ### Documentation
 
 ### Bug fixes
@@ -32,7 +36,7 @@
 
 This release contains contributions from (in alphabetical order):
 
-Vincent Michaud-Rioux, Lee J. O'Riordan
+Ali Asadi, Vincent Michaud-Rioux, Lee J. O'Riordan
 
 ---
 

CMakeLists.txt

@@ -89,8 +89,21 @@ add_subdirectory(pennylane_lightning/core/src)
 #####################################################
 add_library(pennylane_lightning INTERFACE)
 
-target_include_directories(pennylane_lightning  INTERFACE "$<INSTALL_INTERFACE:${PROJECT_SOURCE_DIR}/pennylane_lightning/src;include>")
+target_link_libraries(pennylane_lightning INTERFACE lightning_observables
+                                                    lightning_utils
+                                                    lightning_algorithms
+                                                    )
+
+target_link_libraries(pennylane_lightning INTERFACE  ${PL_BACKEND} #simulator
+                                                    "${PL_BACKEND}_algorithms"
+                                                    "${PL_BACKEND}_observables"
+                                                    "${PL_BACKEND}_bindings"
+                                                    "${PL_BACKEND}_measurements"
+)
+
+target_include_directories(pennylane_lightning  INTERFACE "$<INSTALL_INTERFACE:${PROJECT_SOURCE_DIR}/pennylane_lightning/core/src;include>")
 
+#####################################################
 if(ENABLE_PYTHON)
     message(STATUS "ENABLE_PYTHON is ON.")
     pybind11_add_module("${PL_BACKEND}_ops" "pennylane_lightning/core/src/bindings/Bindings.cpp")

pennylane_lightning/core/_version.py

@@ -16,4 +16,4 @@
    Version number (major.minor.patch[-label])
 """
 
-__version__ = "0.33.0-dev4"
+__version__ = "0.33.0-dev5"

pennylane_lightning/core/src/simulators/base/StateVectorBase.hpp

@@ -41,7 +41,7 @@ namespace Pennylane {
  * @tparam Derived Type of a derived class
  */
 template <class PrecisionT, class Derived> class StateVectorBase {
-  private:
+  protected:
     size_t num_qubits_{0};
 
   public:

pennylane_lightning/core/src/simulators/lightning_qubit/measurements/MeasurementsLQubit.hpp

@@ -247,17 +247,22 @@ class Measurements final
     auto expval(const Observable<StateVectorT> &ob) -> PrecisionT {
         PrecisionT result{};
 
-        if constexpr (std::is_same_v<StateVectorLQubitManaged<PrecisionT>,
-                                     StateVectorT>) {
+        if constexpr (std::is_same_v<typename StateVectorT::MemoryStorageT,
+                                     MemoryStorageLocation::Internal>) {
             StateVectorT sv(this->_statevector);
             result = calculateObsExpval(sv, ob, this->_statevector);
-        } else if constexpr (std::is_same_v<StateVectorLQubitRaw<PrecisionT>,
-                                            StateVectorT>) {
+        } else if constexpr (std::is_same_v<
+                                 typename StateVectorT::MemoryStorageT,
+                                 MemoryStorageLocation::External>) {
             std::vector<ComplexT> data_storage(
                 this->_statevector.getData(),
                 this->_statevector.getData() + this->_statevector.getLength());
             StateVectorT sv(data_storage.data(), data_storage.size());
             result = calculateObsExpval(sv, ob, this->_statevector);
+        } else {
+            /// LCOV_EXCL_START
+            PL_ABORT("Undefined memory storage location for StateVectorT.");
+            /// LCOV_EXCL_STOP
         }
 
         return result;
@@ -271,18 +276,23 @@ class Measurements final
      */
     auto var(const Observable<StateVectorT> &ob) -> PrecisionT {
         PrecisionT result{};
-        if constexpr (std::is_same_v<StateVectorLQubitManaged<PrecisionT>,
-                                     StateVectorT>) {
+        if constexpr (std::is_same_v<typename StateVectorT::MemoryStorageT,
+                                     MemoryStorageLocation::Internal>) {
             StateVectorT sv(this->_statevector);
             result = calculateObsVar(sv, ob, this->_statevector);
 
-        } else if constexpr (std::is_same_v<StateVectorLQubitRaw<PrecisionT>,
-                                            StateVectorT>) {
+        } else if constexpr (std::is_same_v<
+                                 typename StateVectorT::MemoryStorageT,
+                                 MemoryStorageLocation::External>) {
             std::vector<ComplexT> data_storage(
                 this->_statevector.getData(),
                 this->_statevector.getData() + this->_statevector.getLength());
             StateVectorT sv(data_storage.data(), data_storage.size());
             result = calculateObsVar(sv, ob, this->_statevector);
+        } else {
+            /// LCOV_EXCL_START
+            PL_ABORT("Undefined memory storage location for StateVectorT.");
+            /// LCOV_EXCL_STOP
         }
         return result;
     }

pennylane_lightning/core/src/simulators/lightning_qubit/observables/ObservablesLQubit.hpp

@@ -159,8 +159,8 @@ template <class StateVectorT, bool use_openmp> struct HamiltonianApplyInPlace {
     run(const std::vector<PrecisionT> &coeffs,
         const std::vector<std::shared_ptr<Observable<StateVectorT>>> &terms,
         StateVectorT &sv) {
-        if constexpr (std::is_same_v<StateVectorLQubitManaged<PrecisionT>,
-                                     StateVectorT>) {
+        if constexpr (std::is_same_v<typename StateVectorT::MemoryStorageT,
+                                     MemoryStorageLocation::Internal>) {
             auto allocator = sv.allocator();
             std::vector<ComplexT, decltype(allocator)> res(
                 sv.getLength(), ComplexT{0.0, 0.0}, allocator);
@@ -171,8 +171,9 @@ template <class StateVectorT, bool use_openmp> struct HamiltonianApplyInPlace {
                             tmp.getData(), res.data());
             }
             sv.updateData(res);
-        } else if constexpr (std::is_same_v<StateVectorLQubitRaw<PrecisionT>,
-                                            StateVectorT>) {
+        } else if constexpr (std::is_same_v<
+                                 typename StateVectorT::MemoryStorageT,
+                                 MemoryStorageLocation::External>) {
             std::vector<ComplexT> res(sv.getLength(), ComplexT{0.0, 0.0});
             for (size_t term_idx = 0; term_idx < coeffs.size(); term_idx++) {
                 std::vector<ComplexT> tmp_data_storage(
@@ -184,6 +185,10 @@ template <class StateVectorT, bool use_openmp> struct HamiltonianApplyInPlace {
                             tmp.getData(), res.data());
             }
             sv.updateData(res);
+        } else {
+            /// LCOV_EXCL_START
+            PL_ABORT("Undefined memory storage location for StateVectorT.");
+            /// LCOV_EXCL_STOP
         }
     }
 };