diff --git a/src/atom.cpp b/src/atom.cpp
index 0b448a5433..3a3d537ce3 100644
--- a/src/atom.cpp
+++ b/src/atom.cpp
@@ -54,6 +54,15 @@ using namespace MathConst;
 #define DELTA_PERATOM 64
 #define EPSILON 1.0e-6
 
+/* ----------------------------------------------------------------------
+   one instance per AtomVec style in style_atom.h
+------------------------------------------------------------------------- */
+
+template <typename T> static AtomVec *avec_creator(LAMMPS *lmp)
+{
+  return new T(lmp);
+}
+
 /* ---------------------------------------------------------------------- */
 
 /** \class LAMMPS_NS::Atom
@@ -743,16 +752,6 @@ AtomVec *Atom::new_avec(const std::string &style, int trysuffix, int &sflag)
   return nullptr;
 }
 
-/* ----------------------------------------------------------------------
-   one instance per AtomVec style in style_atom.h
-------------------------------------------------------------------------- */
-
-template <typename T>
-AtomVec *Atom::avec_creator(LAMMPS *lmp)
-{
-  return new T(lmp);
-}
-
 /* ---------------------------------------------------------------------- */
 
 void Atom::init()
diff --git a/src/atom.h b/src/atom.h
index ad8349d11c..2c1acb7805 100644
--- a/src/atom.h
+++ b/src/atom.h
@@ -416,9 +416,6 @@ class Atom : protected Pointers {
   void set_atomflag_defaults();
   void setup_sort_bins();
   int next_prime(int);
-
- private:
-  template <typename T> static AtomVec *avec_creator(LAMMPS *);
 };
 
 }    // namespace LAMMPS_NS
diff --git a/src/domain.cpp b/src/domain.cpp
index 22c38c977a..29244dff6a 100644
--- a/src/domain.cpp
+++ b/src/domain.cpp
@@ -47,6 +47,15 @@ using namespace LAMMPS_NS;
 #define DELTAREGION 4
 #define BONDSTRETCH 1.1
 
+/* ----------------------------------------------------------------------
+   one instance per region style in style_region.h
+------------------------------------------------------------------------- */
+
+template <typename T> static Region *region_creator(LAMMPS *lmp, int narg, char ** arg)
+{
+  return new T(lmp, narg, arg);
+}
+
 /* ----------------------------------------------------------------------
    default is periodic
 ------------------------------------------------------------------------- */
@@ -1797,16 +1806,6 @@ void Domain::add_region(int narg, char **arg)
   nregion++;
 }
 
-/* ----------------------------------------------------------------------
-   one instance per region style in style_region.h
-------------------------------------------------------------------------- */
-
-template <typename T>
-Region *Domain::region_creator(LAMMPS *lmp, int narg, char ** arg)
-{
-  return new T(lmp, narg, arg);
-}
-
 /* ----------------------------------------------------------------------
    delete a region
 ------------------------------------------------------------------------- */
diff --git a/src/domain.h b/src/domain.h
index a3a526610e..68ff5aece5 100644
--- a/src/domain.h
+++ b/src/domain.h
@@ -175,9 +175,6 @@ class Domain : protected Pointers {
 
  protected:
   double small[3];    // fractions of box lengths
-
- private:
-  template <typename T> static Region *region_creator(LAMMPS *, int, char **);
 };
 
 }    // namespace LAMMPS_NS
diff --git a/src/neighbor.cpp b/src/neighbor.cpp
index 74bb3bf762..489d76eaed 100644
--- a/src/neighbor.cpp
+++ b/src/neighbor.cpp
@@ -100,6 +100,14 @@ static const char cite_neigh_multi[] =
   " year = {2020}\n"
   "}\n\n";
 
+// template for factory functions:
+// there will be one instance for each style keyword in the respective style_xxx.h files
+
+template <typename S, typename T> static S *style_creator(LAMMPS *lmp)
+{
+  return new T(lmp);
+}
+
 //#define NEIGH_LIST_DEBUG 1
 
 /* ---------------------------------------------------------------------- */
@@ -693,7 +701,7 @@ void Neighbor::init_styles()
 #define NBIN_CLASS
 #define NBinStyle(key,Class,bitmasks) \
   binnames[nbclass] = (char *) #key; \
-  binclass[nbclass] = &bin_creator<Class>; \
+  binclass[nbclass] = &style_creator<NBin, Class>;   \
   binmasks[nbclass++] = bitmasks;
 #include "style_nbin.h"  // IWYU pragma: keep
 #undef NBinStyle
@@ -717,7 +725,7 @@ void Neighbor::init_styles()
 #define NSTENCIL_CLASS
 #define NStencilStyle(key,Class,bitmasks) \
   stencilnames[nsclass] = (char *) #key; \
-  stencilclass[nsclass] = &stencil_creator<Class>; \
+  stencilclass[nsclass] = &style_creator<NStencil, Class>;   \
   stencilmasks[nsclass++] = bitmasks;
 #include "style_nstencil.h"  // IWYU pragma: keep
 #undef NStencilStyle
@@ -741,7 +749,7 @@ void Neighbor::init_styles()
 #define NPAIR_CLASS
 #define NPairStyle(key,Class,bitmasks) \
   pairnames[npclass] = (char *) #key; \
-  pairclass[npclass] = &pair_creator<Class>; \
+  pairclass[npclass] = &style_creator<NPair, Class>;  \
   pairmasks[npclass++] = bitmasks;
 #include "style_npair.h"  // IWYU pragma: keep
 #undef NPairStyle
@@ -2028,36 +2036,6 @@ int Neighbor::request(void *requestor, int instance)
   return nrequest-1;
 }
 
-/* ----------------------------------------------------------------------
-   one instance per entry in style_neigh_bin.h
-------------------------------------------------------------------------- */
-
-template <typename T>
-NBin *Neighbor::bin_creator(LAMMPS *lmp)
-{
-  return new T(lmp);
-}
-
-/* ----------------------------------------------------------------------
-   one instance per entry in style_neigh_stencil.h
-------------------------------------------------------------------------- */
-
-template <typename T>
-NStencil *Neighbor::stencil_creator(LAMMPS *lmp)
-{
-  return new T(lmp);
-}
-
-/* ----------------------------------------------------------------------
-   one instance per entry in style_neigh_pair.h
-------------------------------------------------------------------------- */
-
-template <typename T>
-NPair *Neighbor::pair_creator(LAMMPS *lmp)
-{
-  return new T(lmp);
-}
-
 /* ----------------------------------------------------------------------
    setup neighbor binning and neighbor stencils
    called before run and every reneighbor if box size/shape changes
diff --git a/src/neighbor.h b/src/neighbor.h
index 60687525a3..45468c0c9b 100644
--- a/src/neighbor.h
+++ b/src/neighbor.h
@@ -231,10 +231,6 @@ class Neighbor : protected Pointers {
   int choose_stencil(class NeighRequest *);
   int choose_pair(class NeighRequest *);
 
-  template <typename T> static NBin *bin_creator(class LAMMPS *);
-  template <typename T> static NStencil *stencil_creator(class LAMMPS *);
-  template <typename T> static NPair *pair_creator(class LAMMPS *);
-
   // dummy functions provided by NeighborKokkos, called in init()
   // otherwise NeighborKokkos would have to overwrite init()
 
diff --git a/src/output.cpp b/src/output.cpp
index 1376d365d8..a3c79d4cda 100644
--- a/src/output.cpp
+++ b/src/output.cpp
@@ -43,6 +43,15 @@ using namespace LAMMPS_NS;
 
 enum {SETUP, WRITE, RESET_DT};
 
+/* ----------------------------------------------------------------------
+   one instance per dump style in style_dump.h
+------------------------------------------------------------------------- */
+
+template <typename T> static Dump *dump_creator(LAMMPS *lmp, int narg, char ** arg)
+{
+  return new T(lmp, narg, arg);
+}
+
 /* ----------------------------------------------------------------------
    initialize all output
 ------------------------------------------------------------------------- */
@@ -784,16 +793,6 @@ void Output::add_dump(int narg, char **arg)
   ndump++;
 }
 
-/* ----------------------------------------------------------------------
-   one instance per dump style in style_dump.h
-------------------------------------------------------------------------- */
-
-template <typename T>
-Dump *Output::dump_creator(LAMMPS *lmp, int narg, char ** arg)
-{
-  return new T(lmp, narg, arg);
-}
-
 /* ----------------------------------------------------------------------
    modify parameters of a Dump
 ------------------------------------------------------------------------- */
diff --git a/src/output.h b/src/output.h
index 14c1de6522..54fc83c380 100644
--- a/src/output.h
+++ b/src/output.h
@@ -93,7 +93,6 @@ class Output : protected Pointers {
   void memory_usage();    // print out memory usage
 
  private:
-  template <typename T> static Dump *dump_creator(LAMMPS *, int, char **);
   void calculate_next_dump(int, int, bigint);
 };
 
diff --git a/src/update.cpp b/src/update.cpp
index da412ee89e..c82a1ddc18 100644
--- a/src/update.cpp
+++ b/src/update.cpp
@@ -1,4 +1,3 @@
-// clang-format off
 /* ----------------------------------------------------------------------
    LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
    https://www.lammps.org/, Sandia National Laboratories
@@ -14,15 +13,15 @@
 
 #include "update.h"
 
-#include "style_integrate.h"  // IWYU pragma: keep
-#include "style_minimize.h"   // IWYU pragma: keep
+#include "style_integrate.h"    // IWYU pragma: keep
+#include "style_minimize.h"     // IWYU pragma: keep
 
 #include "comm.h"
 #include "compute.h"
-#include "integrate.h"
 #include "error.h"
 #include "fix.h"
 #include "force.h"
+#include "integrate.h"
 #include "min.h"
 #include "modify.h"
 #include "neighbor.h"
@@ -32,6 +31,19 @@
 
 using namespace LAMMPS_NS;
 
+// template for factory functions:
+// there will be one instance for each style keyword in the respective style_xxx.h files
+
+template <typename T> static Integrate *integrate_creator(LAMMPS *lmp, int narg, char **arg)
+{
+  return new T(lmp, narg, arg);
+}
+
+template <typename T> static Min *minimize_creator(LAMMPS *lmp)
+{
+  return new T(lmp);
+}
+
 /* ---------------------------------------------------------------------- */
 
 Update::Update(LAMMPS *lmp) : Pointers(lmp)
@@ -67,38 +79,36 @@ Update::Update(LAMMPS *lmp) : Pointers(lmp)
   integrate_map = new IntegrateCreatorMap();
 
 #define INTEGRATE_CLASS
-#define IntegrateStyle(key,Class) \
-  (*integrate_map)[#key] = &integrate_creator<Class>;
-#include "style_integrate.h"   // IWYU pragma: keep
+#define IntegrateStyle(key, Class) (*integrate_map)[#key] = &integrate_creator<Class>;
+#include "style_integrate.h"    // IWYU pragma: keep
 #undef IntegrateStyle
 #undef INTEGRATE_CLASS
 
   minimize_map = new MinimizeCreatorMap();
 
 #define MINIMIZE_CLASS
-#define MinimizeStyle(key,Class) \
-  (*minimize_map)[#key] = &minimize_creator<Class>;
+#define MinimizeStyle(key, Class) (*minimize_map)[#key] = &minimize_creator<Class>;
 #include "style_minimize.h"    // IWYU pragma: keep
 #undef MinimizeStyle
 #undef MINIMIZE_CLASS
 
   str = (char *) "verlet";
-  create_integrate(1,&str,1);
+  create_integrate(1, &str, 1);
 
   str = (char *) "cg";
-  create_minimize(1,&str,1);
+  create_minimize(1, &str, 1);
 }
 
 /* ---------------------------------------------------------------------- */
 
 Update::~Update()
 {
-  delete [] unit_style;
+  delete[] unit_style;
 
-  delete [] integrate_style;
+  delete[] integrate_style;
   delete integrate;
 
-  delete [] minimize_style;
+  delete[] minimize_style;
   delete minimize;
 
   delete integrate_map;
@@ -113,8 +123,10 @@ void Update::init()
   // if neither (e.g. from write_restart) then just return
 
   if (whichflag == 0) return;
-  if (whichflag == 1) integrate->init();
-  else if (whichflag == 2) minimize->init();
+  if (whichflag == 1)
+    integrate->init();
+  else if (whichflag == 2)
+    minimize->init();
 
   // only set first_update if a run or minimize is being performed
 
@@ -131,7 +143,7 @@ void Update::set_units(const char *style)
 
   double dt_old = dt;
 
-  if (strcmp(style,"lj") == 0) {
+  if (strcmp(style, "lj") == 0) {
     force->boltz = 1.0;
     force->hplanck = 1.0;
     force->mvv2e = 1.0;
@@ -152,18 +164,18 @@ void Update::set_units(const char *style)
     dt = 0.005;
     neighbor->skin = 0.3;
 
-  } else if (strcmp(style,"real") == 0) {
+  } else if (strcmp(style, "real") == 0) {
     force->boltz = 0.0019872067;
     force->hplanck = 95.306976368;
     force->mvv2e = 48.88821291 * 48.88821291;
     force->ftm2v = 1.0 / 48.88821291 / 48.88821291;
     force->mv2d = 1.0 / 0.602214129;
     force->nktv2p = 68568.415;
-    force->qqr2e = 332.06371;     // see also force->qqr2d_lammps_real
+    force->qqr2e = 332.06371;    // see also force->qqr2d_lammps_real
     force->qe2f = 23.060549;
     force->vxmu2f = 1.4393264316e4;
     force->xxt2kmu = 0.1;
-    force->e_mass = 1.0/1836.1527556560675;
+    force->e_mass = 1.0 / 1836.1527556560675;
     force->hhmrr2e = 0.0957018663603261;
     force->mvh2r = 1.5339009481951;
     force->angstrom = 1.0;
@@ -173,7 +185,7 @@ void Update::set_units(const char *style)
     dt = 1.0;
     neighbor->skin = 2.0;
 
-  } else if (strcmp(style,"metal") == 0) {
+  } else if (strcmp(style, "metal") == 0) {
     force->boltz = 8.617343e-5;
     force->hplanck = 4.135667403e-3;
     force->mvv2e = 1.0364269e-4;
@@ -194,7 +206,7 @@ void Update::set_units(const char *style)
     dt = 0.001;
     neighbor->skin = 2.0;
 
-  } else if (strcmp(style,"si") == 0) {
+  } else if (strcmp(style, "si") == 0) {
     force->boltz = 1.3806504e-23;
     force->hplanck = 6.62606896e-34;
     force->mvv2e = 1.0;
@@ -215,7 +227,7 @@ void Update::set_units(const char *style)
     dt = 1.0e-8;
     neighbor->skin = 0.001;
 
-  } else if (strcmp(style,"cgs") == 0) {
+  } else if (strcmp(style, "cgs") == 0) {
     force->boltz = 1.3806504e-16;
     force->hplanck = 6.62606896e-27;
     force->mvv2e = 1.0;
@@ -236,7 +248,7 @@ void Update::set_units(const char *style)
     dt = 1.0e-8;
     neighbor->skin = 0.1;
 
-  } else if (strcmp(style,"electron") == 0) {
+  } else if (strcmp(style, "electron") == 0) {
     force->boltz = 3.16681534e-6;
     force->hplanck = 0.1519829846;
     force->mvv2e = 1.06657236;
@@ -257,7 +269,7 @@ void Update::set_units(const char *style)
     dt = 0.001;
     neighbor->skin = 2.0;
 
-  } else if (strcmp(style,"micro") == 0) {
+  } else if (strcmp(style, "micro") == 0) {
     force->boltz = 1.3806504e-8;
     force->hplanck = 6.62606896e-13;
     force->mvv2e = 1.0;
@@ -278,7 +290,7 @@ void Update::set_units(const char *style)
     dt = 2.0;
     neighbor->skin = 0.1;
 
-  } else if (strcmp(style,"nano") == 0) {
+  } else if (strcmp(style, "nano") == 0) {
     force->boltz = 0.013806504;
     force->hplanck = 6.62606896e-4;
     force->mvv2e = 1.0;
@@ -299,15 +311,16 @@ void Update::set_units(const char *style)
     dt = 0.00045;
     neighbor->skin = 0.1;
 
-  } else error->all(FLERR,"Illegal units command");
+  } else
+    error->all(FLERR, "Illegal units command");
 
-  delete [] unit_style;
+  delete[] unit_style;
   unit_style = utils::strdup(style);
 
   // check if timestep was changed from default value
   if (!dt_default && (comm->me == 0)) {
-    error->warning(FLERR,"Changing timestep from {:.6} to {:.6} due to "
-                   "changing units to {}", dt_old, dt, unit_style);
+    error->warning(FLERR, "Changing timestep from {:.6} to {:.6} due to changing units to {}",
+                   dt_old, dt, unit_style);
   }
   dt_default = 1;
 }
@@ -316,24 +329,26 @@ void Update::set_units(const char *style)
 
 void Update::create_integrate(int narg, char **arg, int trysuffix)
 {
-  if (narg < 1) error->all(FLERR,"Illegal run_style command");
+  if (narg < 1) error->all(FLERR, "Illegal run_style command");
 
-  delete [] integrate_style;
+  delete[] integrate_style;
   delete integrate;
 
   int sflag;
 
-  if (narg-1 > 0) {
-    new_integrate(arg[0],narg-1,&arg[1],trysuffix,sflag);
+  if (narg - 1 > 0) {
+    new_integrate(arg[0], narg - 1, &arg[1], trysuffix, sflag);
   } else {
-    new_integrate(arg[0],0,nullptr,trysuffix,sflag);
+    new_integrate(arg[0], 0, nullptr, trysuffix, sflag);
   }
 
   std::string estyle = arg[0];
   if (sflag) {
     estyle += "/";
-    if (sflag == 1) estyle += lmp->suffix;
-    else  estyle += lmp->suffix2;
+    if (sflag == 1)
+      estyle += lmp->suffix;
+    else
+      estyle += lmp->suffix2;
   }
   integrate_style = utils::strdup(estyle);
 }
@@ -342,8 +357,7 @@ void Update::create_integrate(int narg, char **arg, int trysuffix)
    create the Integrate style, first with suffix appended
 ------------------------------------------------------------------------- */
 
-void Update::new_integrate(char *style, int narg, char **arg,
-                           int trysuffix, int &sflag)
+void Update::new_integrate(char *style, int narg, char **arg, int trysuffix, int &sflag)
 {
   if (trysuffix && lmp->suffix_enable) {
     if (lmp->suffix) {
@@ -374,36 +388,28 @@ void Update::new_integrate(char *style, int narg, char **arg,
     return;
   }
 
-  error->all(FLERR,"Illegal integrate style");
-}
-
-/* ----------------------------------------------------------------------
-   one instance per integrate style in style_integrate.h
-------------------------------------------------------------------------- */
-
-template <typename T>
-Integrate *Update::integrate_creator(LAMMPS *lmp, int narg, char ** arg)
-{
-  return new T(lmp, narg, arg);
+  error->all(FLERR, "Illegal integrate style");
 }
 
 /* ---------------------------------------------------------------------- */
 
 void Update::create_minimize(int narg, char **arg, int trysuffix)
 {
-  if (narg < 1) error->all(FLERR,"Illegal run_style command");
+  if (narg < 1) error->all(FLERR, "Illegal run_style command");
 
-  delete [] minimize_style;
+  delete[] minimize_style;
   delete minimize;
 
   int sflag;
-  new_minimize(arg[0],narg-1,&arg[1],trysuffix,sflag);
+  new_minimize(arg[0], narg - 1, &arg[1], trysuffix, sflag);
 
   std::string estyle = arg[0];
   if (sflag) {
     estyle += "/";
-    if (sflag == 1) estyle += lmp->suffix;
-    else estyle += lmp->suffix2;
+    if (sflag == 1)
+      estyle += lmp->suffix;
+    else
+      estyle += lmp->suffix2;
   }
   minimize_style = utils::strdup(estyle);
 }
@@ -412,8 +418,7 @@ void Update::create_minimize(int narg, char **arg, int trysuffix)
    create the Minimize style, first with suffix appended
 ------------------------------------------------------------------------- */
 
-void Update::new_minimize(char *style, int /* narg */, char ** /* arg */,
-                           int trysuffix, int &sflag)
+void Update::new_minimize(char *style, int /* narg */, char ** /* arg */, int trysuffix, int &sflag)
 {
   if (trysuffix && lmp->suffix_enable) {
     if (lmp->suffix) {
@@ -444,17 +449,7 @@ void Update::new_minimize(char *style, int /* narg */, char ** /* arg */,
     return;
   }
 
-  error->all(FLERR,"Illegal minimize style");
-}
-
-/* ----------------------------------------------------------------------
-   one instance per minimize style in style_minimize.h
-------------------------------------------------------------------------- */
-
-template <typename T>
-Min *Update::minimize_creator(LAMMPS *lmp)
-{
-  return new T(lmp);
+  error->all(FLERR, "Illegal minimize style");
 }
 
 /* ----------------------------------------------------------------------
@@ -463,8 +458,8 @@ Min *Update::minimize_creator(LAMMPS *lmp)
 
 void Update::reset_timestep(int narg, char **arg)
 {
-  if (narg != 1) error->all(FLERR,"Illegal reset_timestep command");
-  bigint newstep = utils::bnumeric(FLERR,arg[0],false,lmp);
+  if (narg != 1) error->all(FLERR, "Illegal reset_timestep command");
+  bigint newstep = utils::bnumeric(FLERR, arg[0], false, lmp);
   reset_timestep(newstep);
 }
 
@@ -475,7 +470,7 @@ void Update::reset_timestep(int narg, char **arg)
 
 void Update::reset_timestep(bigint newstep)
 {
-  if (newstep < 0) error->all(FLERR,"Timestep must be >= 0");
+  if (newstep < 0) error->all(FLERR, "Timestep must be >= 0");
 
   bigint oldstep = ntimestep;
   ntimestep = newstep;
@@ -499,7 +494,7 @@ void Update::reset_timestep(bigint newstep)
 
   for (const auto &ifix : modify->get_fix_list())
     if (ifix->time_depend)
-      error->all(FLERR, "Cannot reset timestep with time-dependent fix {} defined",ifix->style);
+      error->all(FLERR, "Cannot reset timestep with time-dependent fix {} defined", ifix->style);
 
   // reset eflag/vflag global so no commands will think eng/virial are current
 
@@ -529,7 +524,7 @@ void Update::reset_timestep(bigint newstep)
 
 void Update::update_time()
 {
-  atime += (ntimestep-atimestep) * dt;
+  atime += (ntimestep - atimestep) * dt;
   atimestep = ntimestep;
 }
 
@@ -540,7 +535,9 @@ void Update::update_time()
 double Update::memory_usage()
 {
   double bytes = 0;
-  if (whichflag == 1) bytes += integrate->memory_usage();
-  else if (whichflag == 2) bytes += minimize->memory_usage();
+  if (whichflag == 1)
+    bytes += integrate->memory_usage();
+  else if (whichflag == 2)
+    bytes += minimize->memory_usage();
   return bytes;
 }
diff --git a/src/update.h b/src/update.h
index 25af895bf3..f763dfa559 100644
--- a/src/update.h
+++ b/src/update.h
@@ -73,9 +73,6 @@ class Update : protected Pointers {
  private:
   void new_integrate(char *, int, char **, int, int &);
   void new_minimize(char *, int, char **, int, int &);
-
-  template <typename T> static Integrate *integrate_creator(LAMMPS *, int, char **);
-  template <typename T> static Min *minimize_creator(LAMMPS *);
 };
 
 }    // namespace LAMMPS_NS