corelib/include/ebcl/Registration.hh

/******************************************************************************/
/* REGISTRATION SUPPORT *******************************************************/
/******************************************************************************/

#ifndef _H_EBCL_REGISTRATION
#define _H_EBCL_REGISTRATION
#include <ebcl/Utilities.hh>
#include <ebcl/Pointers.hh>
namespace ebcl {


/*= REGISTRATION SUPPORT =====================================================*/

/* This class is meant to be used with any class that supports registration of
 * items (for example the VFS to which VFS drivers are added).
 *
 * It must be returned from registration methods, and will serve as a way to
 * unregister an item, either directly using the unregister() method, or
 * automatically when the instance is destroyed (if automatic unregistration
 * is active, which is the default).
 */
class T_RegisteredItem
{
    public:
	using F_Unregister = std::function< void( void* ) >;
	using SP_Unregister = T_SharedPtr< F_Unregister >;

    private:
	using F_Destructor_ = std::function< void( void* ) >;
	using WP_Unregister_ = T_WeakPtr< F_Unregister >;

	bool automatic_;
	WP_Unregister_ unregisterFunction_;
	void* data_;
	F_Destructor_ dataDestructor_;

    public:
	/* Initialise an empty item (indicates registration failure) */
	T_RegisteredItem( ) noexcept;

	/* Initialise a registered item */
	T_RegisteredItem( SP_Unregister& unregisterFunction ,
			void* data ,
			F_Destructor_ destructor ) noexcept;
	template< typename T >
		T_RegisteredItem( SP_Unregister& unregisterFunction ,
				T* data ) noexcept;

	/* Destructor. Will unregister the item if automatic mode is
	 * enabled */
	~T_RegisteredItem( );

	/* Copy is disabled */
	T_RegisteredItem( T_RegisteredItem const& ) = delete;
	T_RegisteredItem& operator =( T_RegisteredItem const& ) = delete;

	/* Move and swap */
	T_RegisteredItem( T_RegisteredItem&& other ) noexcept;
	T_RegisteredItem& operator =( T_RegisteredItem&& other ) noexcept;
	friend M_DECLARE_SWAP( T_RegisteredItem );

	/* Set whether this registrable will unregister automatically when
	 * it is deleted. */
	void automatic( bool v ) noexcept;
	bool automatic( ) const noexcept;

	/* Unregister this item. May be called multiple times; the first
	 * call will unregister the item, other calls will be ignored.
	 */
	void unregister( ) noexcept;

	/* Registration check */
	operator bool( ) const noexcept;

    private:
	void clear( ) noexcept;
	void deleteData( ) noexcept;
};
M_CLASS_POINTERS( RegisteredItem );
M_DECLARE_SWAP( T_RegisteredItem );


} // namespace
#endif // _H_EBCL_REGISTRATION
#include <ebcl/inline/Registration.hh>