From: Daniel Arndt <daniel.arndt@iwr.uni-heidelberg.de>
Date: Sat, 18 Mar 2017 16:50:32 +0000 (+0100)
Subject: Restrict LAPACKFullMatrix::print_formatted to matrix states
X-Git-Tag: v8.5.0-rc1~23^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F4082%2Fhead;p=dealii.git

Restrict LAPACKFullMatrix::print_formatted to matrix states
---

diff --git a/doc/news/changes/incompatibilities/20170318DanielArndt b/doc/news/changes/incompatibilities/20170318DanielArndt
new file mode 100644
index 0000000000..f344ef5ef0
--- /dev/null
+++ b/doc/news/changes/incompatibilities/20170318DanielArndt
@@ -0,0 +1,4 @@
+Changed: LAPACKFullMatrix::print_formatted is only allowed
+if the state is 'matrix' or 'inverse_matrix'.
+<br>
+(Daniel Arndt, 2017/03/18)
diff --git a/include/deal.II/lac/lapack_full_matrix.h b/include/deal.II/lac/lapack_full_matrix.h
index e31861687e..24d80a09a9 100644
--- a/include/deal.II/lac/lapack_full_matrix.h
+++ b/include/deal.II/lac/lapack_full_matrix.h
@@ -592,6 +592,10 @@ public:
    *
    * @arg <tt>threshold</tt>: all entries with absolute value smaller than
    * this are considered zero.
+   *
+   * @note The entries stored resemble a matrix only if the state is either
+   * LAPACKSupport::matrix or LAPACK::inverse_matrix. Otherwise, calling this
+   * function is not allowed.
    */
   void print_formatted (std::ostream       &out,
                         const unsigned int  precision   = 3,
diff --git a/include/deal.II/lac/lapack_support.h b/include/deal.II/lac/lapack_support.h
index 193c63da11..a507df2c14 100644
--- a/include/deal.II/lac/lapack_support.h
+++ b/include/deal.II/lac/lapack_support.h
@@ -26,9 +26,12 @@ DEAL_II_NAMESPACE_OPEN
 namespace LAPACKSupport
 {
   /**
-   * Most LAPACK functions change the contents of the matrix applied to to
-   * something which is not a matrix anymore. Therefore, LAPACK matrix classes
-   * in <tt>deal.II</tt> have a state flag indicating what happened to them.
+   * Most of the LAPACK functions one can apply to a matrix (e.g., by calling
+   * the member functions of this class) change its content in some ways. For
+   * example, they may invert the matrix, or may replace it by a matrix whose
+   * columns represent the eigenvectors of the original content of the matrix.
+   * The elements of this enumeration are therefore used to track what is
+   * currently being stored by this object.
    *
    * @author Guido Kanschat, 2005
    */
diff --git a/source/lac/lapack_full_matrix.cc b/source/lac/lapack_full_matrix.cc
index ad272cc9aa..473167f90a 100644
--- a/source/lac/lapack_full_matrix.cc
+++ b/source/lac/lapack_full_matrix.cc
@@ -985,6 +985,9 @@ LAPACKFullMatrix<number>::print_formatted (
 
   Assert ((!this->empty()) || (this->n_cols()+this->n_rows()==0),
           ExcInternalError());
+  Assert (state == LAPACKSupport::matrix ||
+          state == LAPACKSupport::inverse_matrix,
+          ExcState(state));
 
   // set output format, but store old
   // state