From 084146ce64cf5587ef008d7d11f4e1959c2c98d3 Mon Sep 17 00:00:00 2001
From: wolf <wolf@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Thu, 13 Sep 2001 08:45:12 +0000
Subject: [PATCH] Test the annoying std::advance warning.

git-svn-id: https://svn.dealii.org/trunk@4984 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/aclocal.m4   | 32 ++++++++++++++++++++++++++++++++
 deal.II/configure.in |  1 +
 2 files changed, 33 insertions(+)

diff --git a/deal.II/aclocal.m4 b/deal.II/aclocal.m4
index 0810e8eb30..2ca2ce1e5d 100644
--- a/deal.II/aclocal.m4
+++ b/deal.II/aclocal.m4
@@ -475,3 +475,35 @@ AC_DEFUN(DEAL_II_CHECK_ACE_FORBIDDEN_FLAGS, dnl
     fi
   fi
 )
+
+
+
+dnl gcc versions up to 2.95.3 had a problem with the std::advance function,
+dnl when the number of steps forward was given by an unsigned number, since
+dnl a comparison >=0 was performed on this number which leads to a warning
+dnl that this comparison is always true. This is, at the best, annoying
+dnl since it crops up at several places where std::advance is called from
+dnl inside the library. Check whether the present version of the compiler
+dnl has this problem
+AC_DEFUN(DEAL_II_CHECK_ADVANCE_WARNING, dnl
+  AC_LANG_CPLUSPLUS
+  CXXFLAGS="$CXXFLAGSG -Werror"
+  AC_MSG_CHECKING(for std::advance warning)
+  AC_TRY_COMPILE(
+	[
+#include <map>
+#include <vector>
+	],
+	[
+  std::map<unsigned int, double> m;
+  std::vector<std::pair<unsigned int, double> > v;
+  v.insert (v.end(), m.begin(), m.end());
+	],
+	[
+	  AC_MSG_RESULT(yes)
+	],
+	[
+	  AC_MSG_RESULT(no)
+	]
+  )
+)
diff --git a/deal.II/configure.in b/deal.II/configure.in
index 7440718b3c..f2f7905f4b 100644
--- a/deal.II/configure.in
+++ b/deal.II/configure.in
@@ -258,6 +258,7 @@ if test "$GXX" = yes ; then
 	;;
   esac
 
+  DEAL_II_CHECK_ADVANCE_WARNING
 else
 
   if test "x$GXX_VERSION" = "xibm_xlc" ; then
-- 
2.39.5