    // Copyright (C) 2007  Davis E. King (davis@dlib.net)
    // License: Boost Software License   See LICENSE.txt for the full license.
    #ifndef DLIB_IS_KINd_H_
    #define DLIB_IS_KINd_H_

    #include <vector>

    namespace dlib
    {
        /*!
            This file contains a set of templates that enable you to determine if
            a given type implements an abstract interface defined in one of the
            dlib *_abstract.h files.
        !*/

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

        struct default_is_kind_value { static const bool value = false; };

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

        template <typename T>
        struct is_graph : public default_is_kind_value
        {
            /*!
                - if (T is an implementation of graph/graph_kernel_abstract.h) then
                    - is_graph<T>::value == true
                - else
                    - is_graph<T>::value == false
            !*/
        };

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

        template <typename T>
        struct is_directed_graph : public default_is_kind_value
        {
            /*!
                - if (T is an implementation of directed_graph/directed_graph_kernel_abstract.h) then
                    - is_directed_graph<T>::value == true
                - else
                    - is_directed_graph<T>::value == false
            !*/
        };

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

        template <typename T, typename helper = void>
        struct is_matrix : public default_is_kind_value
        {
            /*!
                - if (T is some kind of matrix expression from the matrix/matrix_exp_abstract.h component) then
                    - is_matrix<T>::value == true
                - else
                    - is_matrix<T>::value == false
            !*/

            // Don't set the helper to anything.  Just let it be void.
            ASSERT_ARE_SAME_TYPE(helper,void);
        };

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

        template <typename T>
        struct is_array2d : public default_is_kind_value
        {
            /*!
                - if (T is an implementation of array2d/array2d_kernel_abstract.h) then
                    - is_array2d<T>::value == true
                - else
                    - is_array2d<T>::value == false
            !*/
        };

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

        template <typename T>
        struct is_array : public default_is_kind_value
        {
            /*!
                - if (T is an implementation of array/array_kernel_abstract.h) then
                    - is_array<T>::value == true
                - else
                    - is_array<T>::value == false
            !*/
        };

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

        template <typename T>
        struct is_std_vector : public default_is_kind_value
        {
            /*!
                - if (T is an implementation of the standard C++ std::vector object) then
                    - is_std_vector<T>::value == true
                - else
                    - is_std_vector<T>::value == false
            !*/
        };

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

        template <typename T>
        struct is_pair : public default_is_kind_value
        {
            /*!
                - if (T is a std::pair object) then
                    - is_std_vector<T>::value == true
                - else
                    - is_std_vector<T>::value == false
            !*/
        };

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

        template <typename T>
        struct is_rand : public default_is_kind_value
        {
            /*!
                - if (T is an implementation of rand/rand_kernel_abstract.h) then
                    - is_rand<T>::value == true
                - else
                    - is_rand<T>::value == false
            !*/
        };

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

        template <typename T>
        struct is_config_reader : public default_is_kind_value
        {
            /*!
                - if (T is an implementation of config_reader/config_reader_kernel_abstract.h) then
                    - is_config_reader<T>::value == true
                - else
                    - is_config_reader<T>::value == false
            !*/
        };

    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------
    //                              Implementation details
    // ----------------------------------------------------------------------------------------
    // ----------------------------------------------------------------------------------------

        template <typename T, typename alloc>
        struct is_std_vector<std::vector<T,alloc> >         { const static bool value = true; };
        template <typename T> struct is_std_vector<T&>      { const static bool value = is_std_vector<T>::value; };
        template <typename T> struct is_std_vector<const T&>{ const static bool value = is_std_vector<T>::value; };
        template <typename T> struct is_std_vector<const T> { const static bool value = is_std_vector<T>::value; };

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

        template <typename T, typename U>
        struct is_pair<std::pair<T,U> > { const static bool value = true; };

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

    }

    #endif // DLIB_IS_KINd_H_