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#ifndef DART_COMMON_SPECIALIZEDFORASPECT_HPP_
#define DART_COMMON_SPECIALIZEDFORASPECT_HPP_

#include "dart/common/Composite.hpp"
#include "dart/common/CompositeJoiner.hpp"
#include "dart/common/Virtual.hpp"

namespace dart {
namespace common {

/// Declaration of the variadic template
template <class... OtherSpecAspects>
class SpecializedForAspect
{
public:
  virtual ~SpecializedForAspect() = default;
};

//==============================================================================
/// SpecializedForAspect allows classes that inherit Composite to have
/// constant-time access to a specific type of Aspect
template <class SpecAspect>
class SpecializedForAspect<SpecAspect> : public virtual Composite
{
public:
  /// Default Constructor
  SpecializedForAspect();

  virtual ~SpecializedForAspect() = default;

  /// Check if this Composite currently has a certain type of Aspect
  template <class T>
  bool has() const;

  /// Get a certain type of Aspect from this Composite
  template <class T>
  T* get();

  /// Get a certain type of Aspect from this Composite
  template <class T>
  const T* get() const;

  /// Make a clone of the aspect and place the clone into this Composite. If
  /// an Aspect of the same type already exists in this Composite, the
  /// existing Aspect will be destroyed.
  template <class T>
  void set(const T* aspect);

  /// Use move semantics to place an aspect into this Composite. If an Aspect
  /// of the same type already exists in this Composite, the existing Aspect
  /// will be destroyed.
  template <class T>
  void set(std::unique_ptr<T>&& aspect);

  /// Construct an Aspect inside of this Composite
  template <class T, typename... Args>
  T* createAspect(Args&&... args);

  /// Remove an Aspect from this Composite
  template <class T>
  void removeAspect();

  /// Remove an Aspect from this Composite, but return its unique_ptr instead
  /// of letting it be deleted. This allows you to safely use move semantics to
  /// transfer an Aspect between two Composites.
  template <class T>
  std::unique_ptr<T> releaseAspect();

  /// Check if this Composite is specialized for a specific type of Aspect
  template <class T>
  static constexpr bool isSpecializedFor();

protected:
  template <class T>
  struct type
  {
  };

  /// Redirect to Composite::has()
  template <class T>
  bool _has(type<T>) const;

  /// Specialized implementation of has()
  bool _has(type<SpecAspect>) const;

  /// Redirect to Composite::get()
  template <class T>
  T* _get(type<T>);

  /// Specialized implementation of get()
  SpecAspect* _get(type<SpecAspect>);

  /// Redirect to Composite::get()
  template <class T>
  const T* _get(type<T>) const;

  /// Specialized implementation of get()
  const SpecAspect* _get(type<SpecAspect>) const;

  /// Redirect to Composite::set()
  ///
  /// Using the type<T> tag for this is not be necessary, but it helps to avoid
  /// confusion between the set() versus _set() function.
  template <class T>
  void _set(type<T>, const T* aspect);

  /// Specialized implementation of set()
  void _set(type<SpecAspect>, const SpecAspect* aspect);

  /// Redirect to Composite::set()
  ///
  /// Using the type<T> tag for this is not be necessary, but it helps to avoid
  /// confusion between the set() versus _set() function.
  template <class T>
  void _set(type<T>, std::unique_ptr<T>&& aspect);

  /// Specialized implementation of set()
  void _set(type<SpecAspect>, std::unique_ptr<SpecAspect>&& aspect);

  /// Redirect to Composite::create()
  template <class T, typename... Args>
  T* _createAspect(type<T>, Args&&... args);

  /// Specialized implementation of create()
  template <typename... Args>
  SpecAspect* _createAspect(type<SpecAspect>, Args&&... args);

  /// Redirect to Composite::erase()
  template <class T>
  void _removeAspect(type<T>);

  /// Specialized implementation of erase()
  void _removeAspect(type<SpecAspect>);

  /// Redirect to Composite::release()
  template <class T>
  std::unique_ptr<T> _releaseAspect(type<T>);

  /// Specialized implementation of release()
  std::unique_ptr<SpecAspect> _releaseAspect(type<SpecAspect>);

  /// Return false
  template <class T>
  static constexpr bool _isSpecializedFor(type<T>);

  /// Return true
  static constexpr bool _isSpecializedFor(type<SpecAspect>);

  /// Iterator that points to the Aspect of this SpecializedForAspect
  Composite::AspectMap::iterator mSpecAspectIterator;
};

//==============================================================================
/// This is the variadic version of the SpecializedForAspect class which
/// allows you to include arbitrarily many specialized types in the
/// specialization.
template <class SpecAspect1, class... OtherSpecAspects>
class SpecializedForAspect<SpecAspect1, OtherSpecAspects...>
  : public CompositeJoiner<
        Virtual<SpecializedForAspect<SpecAspect1> >,
        Virtual<SpecializedForAspect<OtherSpecAspects...> > >
{
public:
  virtual ~SpecializedForAspect() = default;
};

} // namespace common
} // namespace dart

#include "dart/common/detail/SpecializedForAspect.hpp"

#endif // DART_COMMON_SPECIALIZEDFORASPECT_HPP_
