From 2d5dd802386d78117d5ed9ddcbf8bc22ab3cb461 Mon Sep 17 00:00:00 2001
From: Daniel Schemmel <daniel.schemmel@comsys.rwth-aachen.de>
Date: Mon, 7 May 2018 23:33:04 +0200
Subject: [PATCH] The Permutation Matrix' `values` function attempted an
 incorrect conversion. This causes compilation with GCC 8 to fail. I suspect
 it worked previously due to SFINAE.

---
 src/util/lp/permutation_matrix.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/util/lp/permutation_matrix.h b/src/util/lp/permutation_matrix.h
index 3c89b36462e..8e664bba090 100644
--- a/src/util/lp/permutation_matrix.h
+++ b/src/util/lp/permutation_matrix.h
@@ -132,7 +132,7 @@ class permutation_matrix : public tail_matrix<T, X> {
 
         unsigned size() const { return static_cast<unsigned>(m_rev.size()); }
 
-        unsigned * values() const { return m_permutation; }
+        unsigned * values() const { return m_permutation.c_ptr(); }
 
         void resize(unsigned size) {
             unsigned old_size = m_permutation.size();