Refactor OperatorImpl for backend/export

Refactor OperatorImpl for backend/export.

include/aidge/backend/cpu/operator/AbsImpl.hpp

@@ -12,7 +12,7 @@
 #ifndef AIDGE_CPU_OPERATOR_ABSIMPL_H_
 #define AIDGE_CPU_OPERATOR_ABSIMPL_H_
 
-#include "aidge/backend/OperatorImpl.hpp"
+#include "aidge/backend/cpu/operator/OperatorImpl.hpp"
 #include "aidge/operator/Abs.hpp"
 #include "aidge/utils/Registrar.hpp"
 #include "aidge/utils/Types.h"
@@ -20,31 +20,12 @@
 #include <vector>
 
 namespace Aidge {
-// class Abs_Op;
+// Operator implementation entry point for the backend
+using AbsImpl_cpu = OperatorImpl_cpu<Abs_Op,
+    void(const std::size_t, const void*, void*)>;
 
-// compute kernel registry for forward and backward
-class AbsImplForward_cpu
-    : public Registrable<AbsImplForward_cpu, std::tuple<DataType, DataType>, void(const std::size_t, const void*, void*)> {
-};
-class AbsImplBackward_cpu
-    : public Registrable<AbsImplBackward_cpu, std::tuple<DataType, DataType>, void(const std::size_t, const void*, void*)> {
-};
-
-class AbsImpl_cpu : public OperatorImpl {
-public:
-    AbsImpl_cpu(const Abs_Op& op) : OperatorImpl(op, "cpu") {}
-
-    static std::unique_ptr<AbsImpl_cpu> create(const Abs_Op& op) {
-        return std::make_unique<AbsImpl_cpu>(op);
-    }
-
-    Elts_t getNbRequiredProtected(const IOIndex_t inputIdx) const override final;
-    void forward() override;
-};
-
-namespace {
-static Registrar<Abs_Op> registrarAbsImpl_cpu("cpu", Aidge::AbsImpl_cpu::create);
-}
+// Implementation entry point registration to Operator
+REGISTRAR(Abs_Op, "cpu", Aidge::AbsImpl_cpu::create);
 }  // namespace Aidge
 
 #endif /* AIDGE_CPU_OPERATOR_ABSIMPL_H_ */