disallow usage of qeq fixes with incompatible GPU and USER-INTEL packages

src/QEQ/fix_qeq.cpp

@@ -24,6 +24,8 @@
 #include "force.h"
 #include "memory.h"
 #include "neigh_list.h"
+#include "pair.h"
+#include "suffix.h"
 #include "text_file_reader.h"
 #include "update.h"
 
@@ -300,6 +302,12 @@ void FixQEq::setup_pre_force(int vflag)
   if (force->newton_pair == 0)
     error->all(FLERR,"QEQ with 'newton pair off' not supported");
 
+  if (force->pair) {
+    if (force->pair->suffix_flag & (Suffix::INTEL|Suffix::GPU))
+      error->all(FLERR,"QEQ is not compatiple with suffix version "
+                 "of pair style");
+  }
+
   deallocate_storage();
   allocate_storage();
 

src/pair.h

@@ -28,6 +28,8 @@ class Pair : protected Pointers {
   friend class FixGPU;
   friend class FixIntel;
   friend class FixOMP;
+  friend class FixQEq;
+  friend class PairHybrid;
   friend class ThrOMP;
   friend class Info;
 

src/pair_hybrid.cpp

@@ -948,9 +948,7 @@ void PairHybrid::modify_special(int m, int /*narg*/, char **arg)
   special[2] = utils::numeric(FLERR,arg[2],false,lmp);
   special[3] = utils::numeric(FLERR,arg[3],false,lmp);
 
-  // have to cast to PairHybrid to work around C++ access restriction
+  if (styles[m]->suffix_flag & (Suffix::INTEL|Suffix::GPU))
-
-  if (((PairHybrid *)styles[m])->suffix_flag & (Suffix::INTEL|Suffix::GPU))
     error->all(FLERR,"Pair_modify special is not compatible with "
                      "suffix version of hybrid substyle");