Fix and workaround several doxygen issues/warnings

Eigen/src/Core/TriangularMatrix.h

@@ -470,6 +470,8 @@ template<typename _MatrixType, unsigned int _Mode> class TriangularViewImpl<_Mat
       * \a Side==OnTheLeft (the default), or the right-inverse-multiply  \a other * inverse(\c *this) if
       * \a Side==OnTheRight.
       *
+      * Note that the template parameter \c Side can be ommitted, in which case \c Side==OnTheLeft
+      *
       * The matrix \c *this must be triangular and invertible (i.e., all the coefficients of the
       * diagonal must be non zero). It works as a forward (resp. backward) substitution if \c *this
       * is an upper (resp. lower) triangular matrix.
@@ -495,6 +497,8 @@ template<typename _MatrixType, unsigned int _Mode> class TriangularViewImpl<_Mat
       * \warning The parameter is only marked 'const' to make the C++ compiler accept a temporary expression here.
       * This function will const_cast it, so constness isn't honored here.
       *
+      * Note that the template parameter \c Side can be ommitted, in which case \c Side==OnTheLeft
+      *
       * See TriangularView:solve() for the details.
       */
     template<int Side, typename OtherDerived>
@@ -546,6 +550,7 @@ template<typename _MatrixType, unsigned int _Mode> class TriangularViewImpl<_Mat
 * Implementation of triangular evaluation/assignment
 ***************************************************************************/
 
+#ifndef EIGEN_PARSED_BY_DOXYGEN
 // FIXME should we keep that possibility
 template<typename MatrixType, unsigned int Mode>
 template<typename OtherDerived>
@@ -583,6 +588,7 @@ void TriangularViewImpl<MatrixType, Mode, Dense>::lazyAssign(const TriangularBas
   eigen_assert(Mode == int(OtherDerived::Mode));
   internal::call_assignment_no_alias(derived(), other.derived());
 }
+#endif
 
 /***************************************************************************
 * Implementation of TriangularBase methods