Summarize incompatible changes.

This list is a bit subjective: I suspect users are not using some of the
changed interfaces that deal with, e.g., implementing hp FEM.

diff --git a/9.1/paper.tex b/9.1/paper.tex
index aed9c8aeedea68894e87de5d87c636906a58f101..346c226ebc9c807f3174b6131f4ed835baf3bd83 100644 (file)
--- a/9.1/paper.tex
+++ b/9.1/paper.tex
@@ -404,7 +404,6 @@ talk about the new programs; also mention updating for C++11 style
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \subsection{Incompatible changes}
 
-\marginpar{Update after the release}
 The 9.1 release includes
 \href{https://dealii.org/developer/doxygen/deal.II/changes_between_9_0_1_and_9_1_0.html}
      {around 15 incompatible changes}; see \cite{changes91}. The majority of these changes
@@ -413,7 +412,21 @@ deprecated classes and functions, and the majority change internal
 interfaces that are not usually used in external
 applications. However, some are worth mentioning:
 \begin{itemize}
-\item TODO
+\item The \texttt{VectorView} class was removed. We recommend either copying the
+      vector subset into a \texttt{Vector} or using a \texttt{BlockVector}.
+\item The function \texttt{Subscriptor::subscribe} now requires a pointer to a
+      \texttt{std::atomic<bool>} that tracks whether or not the pointer to the
+      subscribed-to object is still valid.
+\item The \texttt{ConstraintMatrix} class gained a template parameter for scalar
+      type and was been renamed \texttt{AffineConstraints}. Several methods that
+      take vectors or matrices as arguments,
+      such as \texttt{AffineConstraints::distribute\_local\_to\_global()},
+      now require that all matrix and vector arguments have matching number
+      types.
+\item Similarly, the functions \texttt{create\_mass\_matrix} and
+      \texttt{create\_boundary\_mass\_matrix} in the \texttt{MatrixCreator}
+      namespace no longer
+      support matrix and vector objects of different types.
 \end{itemize}