gcc-7 fails the build as:
  clients/memflush.cc: In function 'int main(int, char**)':
  clients/memflush.cc:42:22: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   if (opt_servers == false)
                      ^~~~~

opt_servers is declated as 'static char *opt_servers= NULL;'
diff --git a/clients/memflush.cc b/clients/memflush.cc
index 8bd0dbf..7641b88 100644
--- a/clients/memflush.cc
+++ b/clients/memflush.cc
@@ -39,7 +39,7 @@ int main(int argc, char *argv[])
 {
   options_parse(argc, argv);
 
-  if (opt_servers == false)
+  if (!opt_servers)
   {
     char *temp;
 
@@ -48,7 +48,7 @@ int main(int argc, char *argv[])
       opt_servers= strdup(temp);
     }
 
-    if (opt_servers == false)
+    if (!opt_servers)
     {
       std::cerr << "No Servers provided" << std::endl;
       exit(EXIT_FAILURE);