doc/C05_TutorialAdvancedInitialization.dox

namespace Eigen {

/** \page TutorialAdvancedInitialization Tutorial - Advanced initialization
    \ingroup Tutorial

\section TutorialMatrixArithmCommaInitializer Comma initializer

Eigen offers a comma initializer syntax which allows to set all the coefficients
of any dense objects (matrix, vector, array, block, etc.) to specific values:
\include Tutorial_commainit_01.cpp
Output: \verbinclude Tutorial_commainit_01.out

Moreover, the elements of the initialization list may themselves be Eigen expressions:
\include Tutorial_commainit_02.cpp
Output: \verbinclude Tutorial_commainit_02.out

<span class="note">\b Side \b note: here \link CommaInitializer::finished() .finished() \endlink
is used to get the actual matrix object once the comma initialization
of our temporary submatrix is done. Note that despite the apparent complexity of such an expression,
Eigen's comma initializer usually compiles to very optimized code without any overhead.</span>


TODO mention using the comma initializer to fill a block xpr like m.row(i) << 1,2,3;

TODO add more sections about Identity(), Zero(), Constant(), Random(), LinSpaced().

*/

}