    // Copyright (C) 2003  Davis E. King (davis@dlib.net)
    // License: Boost Software License   See LICENSE.txt for the full license.
    #ifndef DLIB_HASH_SET_KERNEl_C_
    #define DLIB_HASH_SET_KERNEl_C_

    #include "hash_set_kernel_abstract.h"
    #include "../algs.h"
    #include "../assert.h"

    namespace dlib
    {

        template <
            typename hash_set_base
            >
        class hash_set_kernel_c : public hash_set_base
        {
            typedef typename hash_set_base::type T;
            public:

                void add (
                    T& item
                );

                void remove_any (
                    T& item
                );

                void remove (
                    const T& item,
                    T& item_copy
                );

                void destroy (
                    const T& item
                );

                const T& element (
                ) const;

                const T& element (
                );

        };

        template <
            typename hash_set_base
            >
        inline void swap (
            hash_set_kernel_c<hash_set_base>& a,
            hash_set_kernel_c<hash_set_base>& b
        ) { a.swap(b); }

    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------
        // member function definitions
    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------

        template <
            typename hash_set_base
            >
        void hash_set_kernel_c<hash_set_base>::
        add(
            T& item
        )
        {
            // make sure requires clause is not broken
            DLIB_CASSERT( !this->is_member(item),
                "\tvoid hash_set::add"
                << "\n\titem being added must not already be in the hash_set"
                << "\n\tthis: " << this
                );

            // call the real function
            hash_set_base::add(item);
        }

    // ----------------------------------------------------------------------------------------

        template <
            typename hash_set_base
            >
        void hash_set_kernel_c<hash_set_base>::
        remove (
            const T& item,
            T& item_copy
        )
        {
            // make sure requires clause is not broken
            DLIB_CASSERT( this->is_member(item) &&
                    (static_cast<const void*>(&item) != static_cast<void*>(&item_copy)),
                "\tvoid hash_set::remove"
                << "\n\titem should be in the hash_set if it's going to be removed"
                << "\n\tthis:       " << this
                << "\n\t&item:      " << &item
                << "\n\t&item_copy: " << &item_copy
                );

            // call the real function
            hash_set_base::remove(item,item_copy);
        }

    // ----------------------------------------------------------------------------------------

        template <
            typename hash_set_base
            >
        void hash_set_kernel_c<hash_set_base>::
        destroy (
            const T& item
        )
        {
            // make sure requires clause is not broken
            DLIB_CASSERT( this->is_member(item),
                "\tvoid hash_set::destroy"
                << "\n\titem should be in the hash_set if it's going to be removed"
                << "\n\tthis:       " << this
                << "\n\t&item:      " << &item
                );

            // call the real function
            hash_set_base::destroy(item);
        }

    // ----------------------------------------------------------------------------------------

        template <
            typename hash_set_base
            >
        void hash_set_kernel_c<hash_set_base>::
        remove_any (
            T& item
        )
        {
            // make sure requires clause is not broken
            DLIB_CASSERT( this->size() != 0,
                "\tvoid hash_set::remove_any"
                << "\n\tsize must be greater than zero if an item is to be removed"
                << "\n\tthis: " << this
                );

            // call the real function
            hash_set_base::remove_any(item);
        }

    // ----------------------------------------------------------------------------------------

        template <
            typename hash_set_base
            >
        const typename hash_set_base::type& hash_set_kernel_c<hash_set_base>::
        element (
        ) const
        {
            DLIB_CASSERT(this->current_element_valid() == true,
                "\tconst T& hash_set::element()"
                << "\n\tyou can't access the current element if it doesn't exist"
                << "\n\tthis: " << this
                );

            return hash_set_base::element();
        }

    // ----------------------------------------------------------------------------------------

        template <
            typename hash_set_base
            >
        const typename hash_set_base::type& hash_set_kernel_c<hash_set_base>::
        element (
        )
        {
            DLIB_CASSERT(this->current_element_valid() == true,
                "\tT& hash_set::element()"
                << "\n\tyou can't access the current element if it doesn't exist"
                << "\n\tthis: " << this
                );

            return hash_set_base::element();
        }

    // ----------------------------------------------------------------------------------------

    }

    #endif // DLIB_HASH_SET_KERNEl_C_