    // Copyright (C) 2006  Davis E. King (davis@dlib.net)
    // License: Boost Software License   See LICENSE.txt for the full license.
    #undef DLIB_MATRIx_MAT_ABSTRACT_H__
    #ifdef DLIB_MATRIx_MAT_ABSTRACT_H__

    #include "matrix_abstract.h"
    #inclue <vector>
    #include "../array/array_kernel_abstract.h"
    #include "../array2d/array2d_kernel_abstract.h"

    namespace dlib
    {

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

        template <
            typename EXP
            >
        const matrix_exp<EXP>& mat (
            const matrix_exp<EXP>& m
        );
        /*!
            ensures
                - returns m
                  (i.e. this function just returns the input matrix without any modifications)
        !*/

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

        template <
            typename T,
            typename MM
            >
        const matrix_exp mat (
            const array2d<T,MM>& array
        );
        /*!
            ensures
                - returns a matrix R such that:
                    - R.nr() == array.nr()
                    - R.nc() == array.nc()
                    - for all valid r and c:
                      R(r, c) == array[r][c]
        !*/

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

        template <
            typename T,
            typename MM
            >
        const matrix_exp mat (
            const array<T,MM>& m
        );
        /*!
            ensures
                - returns a matrix R such that:
                    - is_col_vector(R) == true
                    - R.size() == m.size()
                    - for all valid r:
                      R(r) == m[r]
        !*/

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

        template <
            typename value_type,
            typename alloc
            >
        const matrix_exp mat (
            const std::vector<value_type,alloc>& vector
        );
        /*!
            ensures
                - returns a matrix R such that:
                    - is_col_vector(R) == true
                    - R.size() == vector.size()
                    - for all valid r:
                      R(r) == vector[r]
        !*/

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

        template <
            typename value_type,
            typename alloc
            >
        const matrix_exp mat (
            const std_vector_c<value_type,alloc>& vector
        );
        /*!
            ensures
                - returns a matrix R such that:
                    - is_col_vector(R) == true
                    - R.size() == vector.size()
                    - for all valid r:
                      R(r) == vector[r]
        !*/

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

        template <
            typename T
            >
        const matrix_exp mat (
            const T* ptr,
            long nr
        );
        /*!
            requires
                - nr > 0
                - ptr == a pointer to at least nr T objects
            ensures
                - returns a matrix M such that:
                    - M.nr() == nr
                    - m.nc() == 1
                    - for all valid i:
                      M(i) == ptr[i]
                - Note that the returned matrix doesn't take "ownership" of
                  the pointer and thus will not delete or free it.
        !*/

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

        template <
            typename T
            >
        const matrix_exp mat (
            const T* ptr,
            long nr,
            long nc
        );
        /*!
            requires
                - nr > 0
                - nc > 0
                - ptr == a pointer to at least nr*nc T objects
            ensures
                - returns a matrix M such that:
                    - M.nr() == nr
                    - m.nc() == nc
                    - for all valid r and c:
                      M(r,c) == ptr[r*nc + c]
                      (i.e. the pointer is interpreted as a matrix laid out in memory
                      in row major order)
                - Note that the returned matrix doesn't take "ownership" of
                  the pointer and thus will not delete or free it.
        !*/

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

        template <
            typename T
            >
        const matrix_exp mat (
            const ::arma::Mat<T>& m
        );
        /*!
            ensures
                - Converts a matrix from the Armadillo library into a dlib matrix.
                - returns a matrix R such that:
                    - R.nr() == m.n_rows
                    - R.nc() == m.n_cols
                    - for all valid r:
                      R(r,c) == m(r,c)
        !*/

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

        template <
            typename _Scalar,
            int _Rows,
            int _Cols,
            int _Options,
            int _MaxRows,
            int _MaxCols
            >
        const matrix_exp mat (
            const ::Eigen::Matrix<_Scalar,_Rows,_Cols,_Options,_MaxRows,_MaxCols>& m
        );
        /*!
            ensures
                - Converts a matrix from the Eigen library into a dlib matrix.
                - returns a matrix R such that:
                    - R.nr() == m.rows()
                    - R.nc() == m.cols()
                    - for all valid r:
                      R(r,c) == m(r,c)
        !*/

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

    }

    #endif // DLIB_MATRIx_MAT_ABSTRACT_H__