text: //=================================================================================================
  /*!
  //  \file blaze/math/adaptors/diagonalmatrix/BaseTemplate.h
  //  \brief Header file for the implementation of the base template of the DiagonalMatrix
  //
  //  Copyright (C) 2013 Klaus Iglberger - All Rights Reserved
  //
  //  This file is part of the Blaze library. You can redistribute it and/or modify it under
  //  the terms of the New (Revised) BSD License. Redistribution and use in source and binary
  //  forms, with or without modification, are permitted provided that the following conditions
  //  are met:
  //
  //  1. Redistributions of source code must retain the above copyright notice, this list of
  //     conditions and the following disclaimer.
  //  2. Redistributions in binary form must reproduce the above copyright notice, this list
  //     of conditions and the following disclaimer in the documentation and/or other materials
  //     provided with the distribution.
  //  3. Neither the names of the Blaze development group nor the names of its contributors
  //     may be used to endorse or promote products derived from this software without specific
  //     prior written permission.
  //
  //  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
  //  EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  //  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
  //  SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  //  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
  //  TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  //  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  //  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  //  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  //  DAMAGE.
  */
  //=================================================================================================
  
  #ifndef _BLAZE_MATH_ADAPTORS_DIAGONALMATRIX_BASETEMPLATE_H_
  #define _BLAZE_MATH_ADAPTORS_DIAGONALMATRIX_BASETEMPLATE_H_
  
  
  //*************************************************************************************************
  // Includes
  //*************************************************************************************************
  
  #include <blaze/math/typetraits/IsColumnMajorMatrix.h>
  #include <blaze/math/typetraits/IsDenseMatrix.h>
  
  
  namespace blaze {
  
  //=================================================================================================
  //
  //  CLASS DEFINITION
  //
  //=================================================================================================
  
  //*************************************************************************************************
  /*!\defgroup diagonal_matrix DiagonalMatrix
  // \ingroup adaptors
  */
  /*!\brief Matrix adapter for diagonal \f$ N \times N \f$ matrices.
  // \ingroup diagonal_matrix
  //
  // \section diagonalmatrix_general General
  //
  // The DiagonalMatrix class template is an adapter for existing dense and sparse matrix types.
  // It inherits the properties and the interface of the given matrix type \a MT and extends it by
  // enforcing the additional invariant that all matrix elements above and below the diagonal are
  // 0 (diagonal matrix). The type of the adapted matrix can be specified via the first template
  // parameter:
  
     \code
     template< typename MT, bool SO, bool DF >
     class DiagonalMatrix;
     \endcode
  
  //  - MT: specifies the type of the matrix to be adapted. DiagonalMatrix can be used with any
  //        non-cv-qualified, non-reference, non-pointer, non-expression dense or sparse matrix
  //        type. Note that the given matrix type must be either resizable (as for instance
  //        HybridMatrix or DynamicMatrix) or must be square at compile time (as for instance
  //        StaticMatrix).
  //  - SO: specifies the storage order (blaze::rowMajor, blaze::columnMajor) of the matrix. This
  //        template parameter doesn't have to be explicitly defined, but is automatically derived
  //        from the first template parameter.
  //  - DF: specifies whether the given matrix type is a dense or sparse matrix type. This template
  //        parameter doesn't have to be defined explicitly, it is automatically derived from the
  //        first template parameter. Defining the parameter explicitly may result in a compilation
  //        error!
  //
  // The following examples give an impression of several possible diagonal matrices:
  
     \code
     using blaze::unaligned;
     using blaze::unpadded;
     using blaze::rowMajor;
     using blaze::columnMajor;
  
     // Definition of a 3x3 row-major dense diagonal matrix with static memory
     blaze::DiagonalMatrix< blaze::StaticMatrix<int,3UL,3UL,rowMajor> > A;
  
     // Definition of a resizable column-major dense diagonal matrix based on HybridMatrix
     blaze::DiagonalMatrix< blaze::HybridMatrix<float,4UL,4UL,columnMajor> B;
  
     // Definition of a resizable row-major dense diagonal matrix based on DynamicMatrix
     blaze::DiagonalMatrix< blaze::DynamicMatrix<double,rowMajor> > C;
  
     // Definition of a fixed-size row-major dense diagonal matrix based on CustomMatrix
     blaze::DiagonalMatrix< blaze::CustomMatrix<double,unaligned,unpadded,rowMajor> > D;
  
     // Definition of a compressed row-major single precision diagonal matrix
     blaze::DiagonalMatrix< blaze::CompressedMatrix<float,rowMajor> > E;
     \endcode
  
  // The storage order of a diagonal matrix is depending on the storage order of the adapted matrix
  // type \a MT. In case the adapted matrix is stored in a row-wise fashion (i.e. is specified
  // as blaze::rowMajor), the diagonal matrix will also be a row-major matrix. Otherwise, if the
  // adapted matrix is column-major (i.e. is specified as blaze::columnMajor), the diagonal matrix
  // will also be a column-major matrix.
  //
  //
  // \n \section diagonalmatrix_special_properties Special Properties of Diagonal Matrices
  //
  // A diagonal matrix is used exactly like a matrix of the underlying, adapted matrix type \a MT.
  // It also provides (nearly) the same interface as the underlying matrix type. However, there
  // are some important exceptions resulting from the diagonal matrix constraint:
  //
  //  -# <b>\ref diagonalmatrix_square</b>
  //  -# <b>\ref diagonalmatrix_diagonal</b>
  //  -# <b>\ref diagonalmatrix_initialization</b>
  //  -# <b>\ref diagonalmatrix_storage</b>
  //
  // \n \subsection diagonalmatrix_square Diagonal Matrices Must Always be Square!
  //
  // In case a resizable matrix is used (as for instance blaze::HybridMatrix, blaze::DynamicMatrix,
  // or blaze::CompressedMatrix), this means that the according constructors, the \c resize() and
  // the \c extend() functions only expect a single parameter, which specifies both the number of
  // rows and columns, instead of two (one for the number of rows and one for the number of columns):
  
     \code
     using blaze::DynamicMatrix;
     using blaze::DiagonalMatrix;
     using blaze::rowMajor;
  
     // Default constructed, default initialized, row-major 3x3 diagonal dynamic matrix
     DiagonalMatrix< DynamicMatrix<double,rowMajor> > A( 3 );
  
     // Resizing the matrix to 5x5
     A.resize( 5 );
  
     // Extending the number of rows and columns by 2, resulting in a 7x7 matrix
     A.extend( 2 );
     \endcode
  
  // In case a matrix with a fixed size is used (as for instance blaze::StaticMatrix), the number
  // of rows and number of columns must be specified equally:
  
     \code
     using blaze::StaticMatrix;
     using blaze::DiagonalMatrix;
     using blaze::columnMajor;
  
     // Correct setup of a fixed size column-major 3x3 diagonal static matrix
     DiagonalMatrix< StaticMatrix<int,3UL,3UL,columnMajor> > A;
  
     // Compilation error: the provided matrix type is not a square matrix type
     DiagonalMatrix< StaticMatrix<int,3UL,4UL,columnMajor> > B;
     \endcode
  
  // \n \subsection diagonalmatrix_diagonal The Diagonal Matrix Property is Always Enforced!
  //
  // This means that it is only allowed to modify elements on the the diagonal of the matrix, but
  // not the elements in the lower or upper part of the matrix. Also, it is only possible to assign
  // matrices that are diagonal matrices themselves:
  
     \code
     using blaze::CompressedMatrix;
     using blaze::DynamicMatrix;
     using blaze::StaticMatrix;
     using blaze::DiagonalMatrix;
     using blaze::rowMajor;
  
     typedef DiagonalMatrix< CompressedMatrix<double,rowMajor> >  CompressedDiagonal;
  
     // Default constructed, row-major 3x3 diagonal compressed matrix
     CompressedDiagonal A( 3 );
  
     // Initializing elements via the function call operator
     A(0,0) = 1.0;  // Initialization of the diagonal element (0,0)
     A(1,0) = 9.0;  // Throws an exception; invalid modification of lower element
  
     // Inserting more elements via the insert() function
     A.insert( 1, 1, 3.0 );  // Inserting the diagonal element (1,1)
     A.insert( 0, 2, 9.0 );  // Throws an exception; invalid insertion of upper element
  
     // Appending an element via the append() function
     A.reserve( 2, 1 );      // Reserving enough capacity in row 2
     A.append( 2, 2, 5.0 );  // Appending the diagonal element (2,2)
     A.append( 1, 2, 9.0 );  // Throws an exception; appending an element in the upper part
  
     // Access via a non-const iterator
     CompressedDiagonal::Iterator it = A.begin(1);
     *it = 6.0;  // Modifies the element (1,1)
  
     // Erasing elements via the erase() function
     A.erase( 0, 0 );  // Erasing the diagonal element (0,0)
     A.erase( 2, 2 );  // Erasing the diagonal element (2,2)
  
     // Construction from a diagonal dense matrix
     StaticMatrix<double,3UL,3UL> B(  3.0,  0.0,  0.0,
                                      0.0, -2.0,  0.0,
                                      0.0,  0.0,  4.0 );
  
     DiagonalMatrix< DynamicMatrix<double,rowMajor> > C( B );  // OK
  
     // Assignment of a non-diagonal dense matrix
     StaticMatrix<double,3UL,3UL> D(  3.0,  0.0,  9.0,
                                      0.0, -2.0,  0.0,
                                      0.0,  0.0,  4.0 );
  
     C = D;  // Throws an exception; diagonal matrix invariant would be violated!
     \endcode
  
  // The diagonal matrix property is also enforced for diagonal custom matrices: In case the given
  // array of elements does not represent a diagonal matrix, a \a std::invalid_argument exception is
  // thrown:
  
     \code
     using blaze::CustomMatrix;
     using blaze::DiagonalMatrix;
     using blaze::unaligned;
     using blaze::unpadded;
     using blaze::rowMajor;
  
     typedef DiagonalMatrix< CustomMatrix<double,unaligned,unpadded,rowMajor> >  CustomDiagonal;
  
     // Creating a 3x3 diagonal custom matrix from a properly initialized array
     double array[9] = { 1.0, 0.0, 0.0,
                         0.0, 2.0, 0.0,
                         0.0, 0.0, 3.0 };
     CustomDiagonal A( array, 3UL );  // OK
  
     // Attempt to create a second 3x3 diagonal custom matrix from an uninitialized array
     CustomDiagonal B( new double[9UL], 3UL, blaze::ArrayDelete() );  // Throws an exception
     \endcode
  
  // Finally, the diagonal matrix property is enforced for views (rows, columns, submatrices, ...)
  // on the diagonal matrix. The following example demonstrates that modifying the elements of an
  // entire row and submatrix of a diagonal matrix only affects the diagonal matrix elements:
  
     \code
     using blaze::DynamicMatrix;
     using blaze::DiagonalMatrix;
  
     // Setup of the diagonal matrix
     //
     //       ( 0 0 0 0 )
     //   A = ( 0 1 0 0 )
     //       ( 0 0 2 0 )
     //       ( 0 0 0 3 )
     //
     DiagonalMatrix< DynamicMatrix<int> > A( 4 );
     A(1,1) = 1;
     A(2,2) = 2;
     A(3,3) = 3;
  
     // Setting the diagonal element in the 2nd row to 9 results in the matrix
     //
     //       ( 0 0 0 0 )
     //   A = ( 0 1 0 0 )
     //       ( 0 0 9 0 )
     //       ( 0 0 0 3 )
     //
     row( A, 2 ) = 9;
  
     // Setting the diagonal element in the 1st and 2nd column to 7 results in
     //
     //       ( 0 0 0 0 )
     //   A = ( 0 7 0 0 )
     //       ( 0 0 7 0 )
     //       ( 0 0 0 3 )
     //
     submatrix( A, 0, 1, 4, 2 ) = 7;
     \endcode
  
  // The next example demonstrates the (compound) assignment to rows/columns and submatrices of
  // diagonal matrices. Since only diagonal elements may be modified the matrix to be assigned
  // must be structured such that the diagonal matrix invariant of the diagonal matrix is
  // preserved. Otherwise a \a std::invalid_argument exception is thrown:
  
     \code
     using blaze::DynamicMatrix;
     using blaze::DynamicVector;
     using blaze::DiagonalMatrix;
     using blaze::rowVector;
  
     // Setup of two default 4x4 diagonal matrices
     DiagonalMatrix< DynamicMatrix<int> > A1( 4 ), A2( 4 );
  
     // Setup of a 4-dimensional vector
     //
     //   v = ( 0 0 3 0 )
     //
     DynamicVector<int,rowVector> v( 4, 0 );
     v[2] = 3;
  
     // OK: Assigning v to the 2nd row of A1 preserves the diagonal matrix invariant
     //
     //        ( 0 0 0 0 )
     //   A1 = ( 0 0 0 0 )
     //        ( 0 0 3 0 )
     //        ( 0 0 0 0 )
     //
     row( A1, 2 ) = v;  // OK
  
     // Error: Assigning v to the 1st row of A1 violates the diagonal matrix invariant! The element
     //   marked with X cannot be assigned and triggers an exception.
     //
     //        ( 0 0 0 0 )
     //   A1 = ( 0 0 X 0 )
     //        ( 0 0 3 0 )
     //        ( 0 0 0 0 )
     //
     row( A1, 1 ) = v;  // Assignment throws an exception!
  
     // Setup of the 3x2 dynamic matrix
     //
     //       ( 0 0 )
     //   B = ( 2 0 )
     //       ( 0 3 )
     //
     DynamicMatrix<int> B( 3UL, 2UL, 0 );
     B(1,0) = 2;
     B(2,1) = 3;
  
     // OK: Assigning B to a submatrix of A2 such that the diagonal matrix invariant can be preserved
     //
     //        ( 0 0 0 0 )
     //   A2 = ( 0 2 0 0 )
     //        ( 0 0 3 0 )
     //        ( 0 0 0 0 )
     //
     submatrix( A2, 0UL, 1UL, 3UL, 2UL ) = B;  // OK
  
     // Error: Assigning B to a submatrix of A2 such that the diagonal matrix invariant cannot be
     //   preserved! The elements marked with X cannot be assigned without violating the invariant!
     //
     //        ( 0 0 0 0 )
     //   A2 = ( 0 2 X 0 )
     //        ( 0 0 3 X )
     //        ( 0 0 0 0 )
     //
     submatrix( A2, 0UL, 2UL, 3UL, 2UL ) = B;  // Assignment throws an exception!
     \endcode
  
  // \n \subsection diagonalmatrix_initialization The Lower and Upper Elements of a Dense Diagonal Matrix are Always Default Initialized!
  //
  // Although this results in a small loss of efficiency during the creation of a dense diagonal
  // matrix this initialization is important since otherwise the diagonal matrix property of dense
  // diagonal matrices would not be guaranteed:
  
     \code
     using blaze::DynamicMatrix;
     using blaze::DiagonalMatrix;
  
     // Uninitialized, 5x5 row-major diagonal matrix
     DynamicMatrix<int,rowMajor> A( 5, 5 );
  
     // 5x5 row-major diagonal dynamic matrix with default initialized lower and upper matrix
     DiagonalMatrix< DynamicMatrix<int,rowMajor> > B( 5 );
     \endcode
  
  // \n \subsection diagonalmatrix_storage Dense Diagonal Matrices Also Store the Non-diagonal Elements!
  //
  // It is very important to note that dense diagonal matrices store all elements, including the
  // non-diagonal elements, and therefore don't provide any kind of memory reduction! There are
  // two main reasons for this: First, storing also the non-diagonal elements guarantees maximum
  // performance for many algorithms that perform vectorized operations on the diagonal matrix,
  // which is especially true for small dense matrices. Second, conceptually the DiagonalMatrix
  // adaptor merely restricts the interface to the matrix type \a MT and does not change the data
  // layout or the underlying matrix type. Thus, in order to achieve the perfect combination of
  // performance and memory consumption it is recommended to use dense matrices for small diagonal
  // matrices and sparse matrices for large diagonal matrices:
  
     \code
     // Recommendation 1: use dense matrices for small diagonal matrices
     typedef blaze::DiagonalMatrix< blaze::StaticMatrix<float,3UL,3UL> >  SmallDiagonalMatrix;
  
     // Recommendation 2: use sparse matrices for large diagonal matrices
     typedef blaze::DiagonalMatrix< blaze::CompressedMatrix<float> >  LargeDiagonalMatrix;
     \endcode
  
  // \n \section diagonalmatrix_arithmetic_operations Arithmetic Operations
  //
  // A DiagonalMatrix matrix can participate in numerical operations in any way any other dense or
  // sparse matrix can participate. It can also be combined with any other dense or sparse vector
  // or matrix. The following code example gives an impression of the use of DiagonalMatrix within
  // arithmetic operations:
  
     \code
     using blaze::DiagonalMatrix;
     using blaze::DynamicMatrix;
     using blaze::HybridMatrix;
     using blaze::StaticMatrix;
     using blaze::CompressedMatrix;
     using blaze::rowMajor;
     using blaze::columnMajor;
  
     DynamicMatrix<double,rowMajor> A( 3, 3 );
     CompressedMatrix<double,rowMajor> B( 3, 3 );
  
     DiagonalMatrix< DynamicMatrix<double,rowMajor> > C( 3 );
     DiagonalMatrix< CompressedMatrix<double,rowMajor> > D( 3 );
  
     DiagonalMatrix< HybridMatrix<float,3UL,3UL,rowMajor> > E;
     DiagonalMatrix< StaticMatrix<float,3UL,3UL,columnMajor> > F;
  
     E = A + B;     // Matrix addition and assignment to a row-major diagonal matrix
     F = C - D;     // Matrix subtraction and assignment to a column-major diagonal matrix
     F = A * D;     // Matrix multiplication between a dense and a sparse matrix
  
     C *= 2.0;      // In-place scaling of matrix C
     E  = 2.0 * B;  // Scaling of matrix B
     F  = C * 2.0;  // Scaling of matrix C
  
     E += A - B;    // Addition assignment
     F -= C + D;    // Subtraction assignment
     F *= A * D;    // Multiplication assignment
     \endcode
  
  // \n \section diagonalmatrix_block_structured Block-Structured Diagonal Matrices
  //
  // It is also possible to use block-structured diagonal matrices:
  
     \code
     using blaze::CompressedMatrix;
     using blaze::StaticMatrix;
     using blaze::DiagonalMatrix;
  
     // Definition of a 5x5 block-structured diagonal matrix based on CompressedMatrix
     DiagonalMatrix< CompressedMatrix< StaticMatrix<int,3UL,3UL> > > A( 5 );
     \endcode
  
  // Also in this case the diagonal matrix invariant is enforced, i.e. it is not possible to
  // manipulate elements in the lower and upper part of the matrix:
  
     \code
     const StaticMatrix<int,3UL,3UL> B( { { 1, -4,  5 },
                                          { 6,  8, -3 },
                                          { 2, -1,  2 } } )
  
     A.insert( 2, 2, B );  // Inserting the diagonal elements (2,2)
     A(2,4)(1,1) = -5;     // Invalid manipulation of upper matrix element; Results in an exception
     \endcode
  
  // \n \section diagonalmatrix_performance Performance Considerations
  //
  // The \b Blaze library tries to exploit the properties of diagonal matrices whenever and wherever
  // possible. In fact, diagonal matrices come with several special kernels and additionally profit
  // from all optimizations for symmetric and triangular matrices. Thus using a diagonal matrix
  // instead of a general matrix can result in a considerable performance improvement. However,
  // there are also situations when using a diagonal triangular matrix introduces some overhead. The
  // following examples demonstrate several common situations where diagonal matrices can positively
  // or negatively impact performance.
  //
  // \n \subsection diagonalmatrix_matrix_matrix_multiplication Positive Impact: Matrix/Matrix Multiplication
  //
  // When multiplying two matrices, at least one of which is diagonal, \b Blaze can exploit the fact
  // that the lower and upper part of the matrix contains only default elements and restrict the
  // algorithm to the diagonal elements. The following example demonstrates this by means of a dense
  // matrix/dense matrix multiplication:
  
     \code
     using blaze::DynamicMatrix;
     using blaze::DiagonalMatrix;
     using blaze::rowMajor;
     using blaze::columnMajor;
  
     DiagonalMatrix< DynamicMatrix<double,rowMajor> > A;
     DynamicMatrix<double,columnMajor> B, C;
  
     // ... Resizing and initialization
  
     C = A * B;
     \endcode
  
  // In comparison to a general matrix multiplication, the performance advantage is significant,
  // especially for large matrices. In this particular case, the multiplication performs similarly
  // to a matrix addition since the complexity is reduced from \f$ O(N^3) \f$ to \f$ O(N^2) \f$.
  // Therefore is it highly recommended to use the DiagonalMatrix adaptor when a matrix is known
  // to be diagonal. Note however that the performance advantage is most pronounced for dense
  // matrices and much less so for sparse matrices.
  //
  // \n \subsection diagonalmatrix_matrix_vector_multiplication Positive Impact: Matrix/Vector Multiplication
  //
  // A similar performance improvement can be gained when using a diagonal matrix in a matrix/vector
  // multiplication:
  
     \code
     using blaze::DynamicMatrix;
     using blaze::DynamicVector;
     using blaze::DiagonalMatrix;
     using blaze::rowMajor;
     using blaze::columnVector;
  
     DiagonalMatrix< DynamicMatrix<double,rowMajor> > A;
     DynamicVector<double,columnVector> x, y;
  
     // ... Resizing and initialization
  
     y = A * x;
     \endcode
  
  // In this example, \b Blaze also exploits the structure of the matrix and performs similarly to
  // a vector addition. Also in case of matrix/vector multiplications the performance improvement
  // is most pronounced for dense matrices and much less so for sparse matrices.
  //
  // \n \subsection diagonalmatrix_assignment Negative Impact: Assignment of a General Matrix
  //
  // In contrast to using a diagonal matrix on the right-hand side of an assignment (i.e. for read
  // access), which introduces absolutely no performance penalty, using a diagonal matrix on the
  // left-hand side of an assignment (i.e. for write access) may introduce additional overhead when
  // it is assigned a general matrix, which is not diagonal at compile time:
  
     \code
     using blaze::DynamicMatrix;
     using blaze::DiagonalMatrix;
  
     DiagonalMatrix< DynamicMatrix<double> > A, C;
     DynamicMatrix<double> B;
  
     B = A;  // Only read-access to the diagonal matrix; no performance penalty
     C = A;  // Assignment of a diagonal matrix to another diagonal matrix; no runtime overhead
     C = B;  // Assignment of a general matrix to a diagonal matrix; some runtime overhead
     \endcode
  
  // When assigning a general, potentially not diagonal matrix to a diagonal matrix it is necessary
  // to check whether the matrix is diagonal at runtime in order to guarantee the diagonal property
  // of the diagonal matrix. In case it turns out to be diagonal, it is assigned as efficiently as
  // possible, if it is not, an exception is thrown. In order to prevent this runtime overhead it
  // is therefore generally advisable to assign diagonal matrices to other diagonal matrices.\n
  // In this context it is especially noteworthy that the addition, subtraction, and multiplication
  // of two diagonal matrices always results in another diagonal matrix:
  
     \code
     using blaze::DynamicMatrix;
     using blaze::DiagonalMatrix;
  
     DiagonalMatrix< DynamicMatrix<double> > A, B, C;
  
     C = A + B;  // Results in a diagonal matrix; no runtime overhead
     C = A - B;  // Results in a diagonal matrix; no runtime overhead
     C = A * B;  // Results in a diagonal matrix; no runtime overhead
     \endcode
  */
  template< typename MT                               // Type of the adapted matrix
          , bool SO = IsColumnMajorMatrix<MT>::value  // Storage order of the adapted matrix
          , bool DF = IsDenseMatrix<MT>::value >      // Density flag
  class DiagonalMatrix
  {};
  //*************************************************************************************************
  
  } // namespace blaze
  
  #endif
  