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#ifndef __OPENCV_DNN_LAYER_HPP__
#define __OPENCV_DNN_LAYER_HPP__
#include <opencv2/dnn.hpp>

namespace cv
{
namespace dnn
{
//! @addtogroup dnn
//! @{
//!
//! @defgroup LayerFactoryModule Utilities for new layers registration
//! @{

/** @brief %Layer factory allows to create instances of registered layers. */
class CV_EXPORTS LayerFactory
{
public:

    //! Each Layer class must provide this function to the factory
    typedef Ptr<Layer>(*Constuctor)(LayerParams &params);

    //! Registers the layer class with typename @p type and specified @p constructor.
    static void registerLayer(const String &type, Constuctor constructor);

    //! Unregisters registered layer with specified type name.
    static void unregisterLayer(const String &type);

    /** @brief Creates instance of registered layer.
     *  @param type type name of creating layer.
     *  @param params parameters which will be used for layer initialization.
     */
    static Ptr<Layer> createLayerInstance(const String &type, LayerParams& params);

private:
    LayerFactory();

    struct Impl;
    static Ptr<Impl> impl();
};

/** @brief Registers layer constructor in runtime.
*   @param type string, containing type name of the layer.
*   @param constuctorFunc pointer to the function of type LayerRegister::Constuctor, which creates the layer.
*   @details This macros must be placed inside the function code.
*/
#define REG_RUNTIME_LAYER_FUNC(type, constuctorFunc) \
    LayerFactory::registerLayer(#type, constuctorFunc);

/** @brief Registers layer class in runtime.
 *  @param type string, containing type name of the layer.
 *  @param class C++ class, derived from Layer.
 *  @details This macros must be placed inside the function code.
 */
#define REG_RUNTIME_LAYER_CLASS(type, class) \
    LayerFactory::registerLayer(#type, _layerDynamicRegisterer<class>);

/** @brief Registers layer constructor on module load time.
*   @param type string, containing type name of the layer.
*   @param constuctorFunc pointer to the function of type LayerRegister::Constuctor, which creates the layer.
*   @details This macros must be placed outside the function code.
*/
#define REG_STATIC_LAYER_FUNC(type, constuctorFunc) \
static _LayerStaticRegisterer __LayerStaticRegisterer_##type(#type, constuctorFunc);

/** @brief Registers layer class on module load time.
 *  @param type string, containing type name of the layer.
 *  @param class C++ class, derived from Layer.
 *  @details This macros must be placed outside the function code.
 */
#define REG_STATIC_LAYER_CLASS(type, class)                         \
Ptr<Layer> __LayerStaticRegisterer_func_##type(LayerParams &params) \
    { return Ptr<Layer>(new class(params)); }                       \
static _LayerStaticRegisterer __LayerStaticRegisterer_##type(#type, __LayerStaticRegisterer_func_##type);


//! @}
//! @}


template<typename LayerClass>
Ptr<Layer> _layerDynamicRegisterer(LayerParams &params)
{
    return Ptr<Layer>(new LayerClass(params));
}

//allows automatically register created layer on module load time
struct _LayerStaticRegisterer
{
    String type;

    _LayerStaticRegisterer(const String &type, LayerFactory::Constuctor constuctor)
    {
        this->type = type;
        LayerFactory::registerLayer(type, constuctor);
    }

    ~_LayerStaticRegisterer()
    {
        LayerFactory::unregisterLayer(type);
    }
};

}
}
#endif
