Instantiator.h

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// Mantid Repository : https://github.com/mantidproject/mantid
//
// Copyright © 2007 ISIS Rutherford Appleton Laboratory UKRI,
//   NScD Oak Ridge National Laboratory, European Spallation Source,
//   Institut Laue - Langevin & CSNS, Institute of High Energy Physics, CAS
// SPDX - License - Identifier: GPL - 3.0 +
#pragma once
 
#include <memory>
 
namespace Mantid {
namespace Kernel {
template <class Base, typename... Args>
class DLLExport AbstractInstantiator
{
public:
  AbstractInstantiator() = default;
 
  virtual ~AbstractInstantiator() = default;
 
  virtual std::shared_ptr<Base> createInstance(Args... args) const = 0;
 
  virtual Base *createUnwrappedInstance(Args... args) const = 0;
 
private:
  AbstractInstantiator(const AbstractInstantiator &);
  AbstractInstantiator &operator=(const AbstractInstantiator &);
};
 
// A template class for the easy instantiation of
// instantiators.
//
// For the Instantiator to work, the class of which
// instances are to be instantiated must have a no-argument
// constructor.
template <class C, class Base, typename... Args>
class DLLExport Instantiator : public AbstractInstantiator<Base, Args...> {
public:
  Instantiator() = default;
 
  std::shared_ptr<Base> createInstance(Args... args) const override { return std::make_shared<C>(args...); }
 
  Base *createUnwrappedInstance(Args... args) const override { return static_cast<Base *>(new C(args...)); }
};
 
} // namespace Kernel
} // namespace Mantid