try another flag for the dec compiler...

Templates/cxxconfigure

@@ -740,11 +740,11 @@ case $system in
         rm -f conftest*
 	;;      
      OSF1-*)
-        echo $ac_n "checking whether ${CXX} accepts -std strict_ansi""... $ac_c" 1>&6
+        echo $ac_n "checking whether ${CXX} accepts -std strict_ansi -nopure_cname""... $ac_c" 1>&6
         echo 'void f(){}' > conftest.c
-        if test -z "`${CXX} -std strict_ansi -c conftest.c 2>&1`"; then
+        if test -z "`${CXX} -std strict_ansi -nopure_cname -c conftest.c 2>&1`"; then
           echo "$ac_t""yes" 1>&6
-          CMAKE_ANSI_CXXFLAGS="-std strict_ansi"
+          CMAKE_ANSI_CXXFLAGS="-std strict_ansi -nopure_cname"
         else
           echo "$ac_t""no" 1>&6
         fi

Templates/cxxconfigure.in

@@ -76,11 +76,11 @@ case $system in
         rm -f conftest*
 	;;      
      OSF1-*)
-        echo $ac_n "checking whether ${CXX} accepts -std strict_ansi""... $ac_c" 1>&6
+        echo $ac_n "checking whether ${CXX} accepts -std strict_ansi -nopure_cname""... $ac_c" 1>&6
         echo 'void f(){}' > conftest.c
-        if test -z "`${CXX} -std strict_ansi -c conftest.c 2>&1`"; then
+        if test -z "`${CXX} -std strict_ansi -nopure_cname -c conftest.c 2>&1`"; then
           echo "$ac_t""yes" 1>&6
-          CMAKE_ANSI_CXXFLAGS="-std strict_ansi"
+          CMAKE_ANSI_CXXFLAGS="-std strict_ansi -nopure_cname"
         else
           echo "$ac_t""no" 1>&6
         fi

configure

@@ -974,11 +974,11 @@ case $system in
         rm -f conftest*
 	;;     
      OSF1-*)
-        echo $ac_n "checking whether ${CXX} accepts -std strict_ansi""... $ac_c" 1>&6
+        echo $ac_n "checking whether ${CXX} accepts -std strict_ansi -nopure_cname""... $ac_c" 1>&6
         echo 'void f(){}' > conftest.c
-        if test -z "`${CXX} -std strict_ansi -c conftest.c 2>&1`"; then
+        if test -z "`${CXX} -std strict_ansi -nopure_cname -c conftest.c 2>&1`"; then
           echo "$ac_t""yes" 1>&6
-          CMAKE_ANSI_CXXFLAGS="-std strict_ansi"
+          CMAKE_ANSI_CXXFLAGS="-std strict_ansi -nopure_cname"
         else
           echo "$ac_t""no" 1>&6
         fi

configure.in

@@ -89,11 +89,11 @@ case $system in
         rm -f conftest*
 	;;     
      OSF1-*)
-        echo $ac_n "checking whether ${CXX} accepts -std strict_ansi""... $ac_c" 1>&6
+        echo $ac_n "checking whether ${CXX} accepts -std strict_ansi -nopure_cname""... $ac_c" 1>&6
         echo 'void f(){}' > conftest.c
-        if test -z "`${CXX} -std strict_ansi -c conftest.c 2>&1`"; then
+        if test -z "`${CXX} -std strict_ansi -nopure_cname -c conftest.c 2>&1`"; then
           echo "$ac_t""yes" 1>&6
-          CMAKE_ANSI_CXXFLAGS="-std strict_ansi"
+          CMAKE_ANSI_CXXFLAGS="-std strict_ansi -nopure_cname"
         else
           echo "$ac_t""no" 1>&6
         fi