fix Transform documention regarding Mode

Eigen/src/Geometry/Transform.h

diff --git a/Eigen/src/Geometry/Transform.h b/Eigen/src/Geometry/Transform.h
index 2066e68..4542eed 100644
--- a/Eigen/src/Geometry/Transform.h
+++ b/Eigen/src/Geometry/Transform.h
@@ -86,7 +86,6 @@
   * \param _Mode the type of the transformation. Can be:
   *              - Affine: the transformation is stored as a (Dim+1)^2 matrix,
   *                        where the last row is assumed to be [0 ... 0 1].
-  *                        This is the default.
   *              - AffineCompact: the transformation is stored as a (Dim)x(Dim+1) matrix.
   *              - Projective: the transformation is stored as a (Dim+1)^2 matrix
   *                            without any assumption.
@@ -1076,12 +1075,13 @@
   * on \c *this.
   *
   * \param hint allows to optimize the inversion process when the transformation
-  * is known to be not a general transformation. The possible values are:
+  * is known to be not a general transformation (optional). The possible values are:
   *  - Projective if the transformation is not necessarily affine, i.e., if the
   *    last row is not guaranteed to be [0 ... 0 1]
-  *  - Affine is the default, the last row is assumed to be [0 ... 0 1]
+  *  - Affine if the last row can be assumed to be [0 ... 0 1]
   *  - Isometry if the transformation is only a concatenations of translations
   *    and rotations.
+  *  The default is the template class parameter \c Mode.
   *
   * \warning unless \a traits is always set to NoShear or NoScaling, this function
   * requires the generic inverse method of MatrixBase defined in the LU module. If

doc/A05_PortingFrom2To3.dox

diff --git a/doc/A05_PortingFrom2To3.dox b/doc/A05_PortingFrom2To3.dox
index 13839a2..70a8d09 100644
--- a/doc/A05_PortingFrom2To3.dox
+++ b/doc/A05_PortingFrom2To3.dox
@@ -246,7 +246,7 @@
 
 \section Transform The Transform class
 
-In Eigen 2, the Transform class didn't really know whether it was a projective or affine transformation. In Eigen 3, it takes a new \a Mode template parameter, which indicates whether it's \a Projective or \a Affine transform. The default is \a Projective.
+In Eigen 2, the Transform class didn't really know whether it was a projective or affine transformation. In Eigen 3, it takes a new \a Mode template parameter, which indicates whether it's \a Projective or \a Affine transform. There is no default value.
 
 The Transform3f (etc) typedefs are no more. In Eigen 3, the Transform typedefs explicitly refer to the \a Projective and \a Affine modes: