diff --git a/src/sat/sat_solver/inc_sat_solver.cpp b/src/sat/sat_solver/inc_sat_solver.cpp
index 4d92dcb81..07e6d71de 100644
--- a/src/sat/sat_solver/inc_sat_solver.cpp
+++ b/src/sat/sat_solver/inc_sat_solver.cpp
@@ -139,7 +139,7 @@ public:
         if (m_mcs.back()) result->m_mcs.push_back(m_mcs.back()->translate(tr));
         if (m_sat_mc) {
             m_sat_mc->flush_smc(m_solver, m_map);
-            result->m_sat_mc = dynamic_cast<sat2goal::mc*>(m_sat_mc->translate(tr));
+            result->m_sat_mc = static_cast<sat2goal::mc*>(m_sat_mc->translate(tr));
         }
         result->m_has_uninterpreted = m_has_uninterpreted;
         // copy m_bb_rewriter?
diff --git a/src/sat/smt/euf_model.cpp b/src/sat/smt/euf_model.cpp
index 2d665fadf..88071cd56 100644
--- a/src/sat/smt/euf_model.cpp
+++ b/src/sat/smt/euf_model.cpp
@@ -72,7 +72,7 @@ namespace euf {
         model_ref mdl;
         auto s = get_solver(m.mk_family_id("sls"), nullptr);
         if (s)
-            mdl = dynamic_cast<sls::solver*>(s)->get_model();
+            mdl = static_cast<sls::solver*>(s)->get_model();
         return mdl;
     }
 
diff --git a/src/sat/tactic/sat2goal.cpp b/src/sat/tactic/sat2goal.cpp
index c1835f839..ab8b8d8ee 100644
--- a/src/sat/tactic/sat2goal.cpp
+++ b/src/sat/tactic/sat2goal.cpp
@@ -112,7 +112,7 @@ void sat2goal::mc::flush_gmc() {
 model_converter* sat2goal::mc::translate(ast_translation& translator) {
     mc* result = alloc(mc, translator.to());
     result->m_smc.copy(m_smc);
-    result->m_gmc = m_gmc ? dynamic_cast<generic_model_converter*>(m_gmc->translate(translator)) : nullptr;
+    result->m_gmc = m_gmc ? static_cast<generic_model_converter*>(m_gmc->translate(translator)) : nullptr;
     for (expr* e : m_var2expr) {
         result->m_var2expr.push_back(translator(e));
     }
@@ -269,7 +269,7 @@ struct sat2goal::imp {
                 ba->to_formulas(l2e, fmls);
             }
             else 
-                dynamic_cast<euf::solver*>(ext)->to_formulas(l2e, fmls);            
+                static_cast<euf::solver*>(ext)->to_formulas(l2e, fmls);            
             for (expr* f : fmls)
                 r.assert_expr(f);            
         }
diff --git a/src/smt/smt_context.cpp b/src/smt/smt_context.cpp
index 3afc40d81..af460d549 100644
--- a/src/smt/smt_context.cpp
+++ b/src/smt/smt_context.cpp
@@ -1568,7 +1568,7 @@ namespace smt {
         family_id fid = m.get_family_id("specrels");
         theory* th = get_theory(fid);
         if (th)
-            dynamic_cast<theory_special_relations*>(th)->get_specrels(rels);
+            static_cast<theory_special_relations*>(th)->get_specrels(rels);
     }
 
 
@@ -3602,7 +3602,7 @@ namespace smt {
         auto p = m_theories.get_plugin(tid);
         if (!p)
             return false;
-        m_model = dynamic_cast<theory_sls*>(p)->get_model();      
+        m_model = static_cast<theory_sls*>(p)->get_model();
         return m_model.get() != nullptr;
     }
 
diff --git a/src/solver/simplifier_solver.cpp b/src/solver/simplifier_solver.cpp
index ea2a1b2ea..c75d574eb 100644
--- a/src/solver/simplifier_solver.cpp
+++ b/src/solver/simplifier_solver.cpp
@@ -272,7 +272,7 @@ public:
         for (dependent_expr const& f : m_fmls) 
             result->m_fmls.push_back(dependent_expr(tr, f));
         if (m_mc) 
-            result->m_mc = dynamic_cast<generic_model_converter*>(m_mc->translate(tr));
+            result->m_mc = m_mc->translate(tr);
 
         // copy m_preprocess_state?
         return result;
diff --git a/src/solver/solver_pool.cpp b/src/solver/solver_pool.cpp
index 27c6e305c..c98a2b57a 100644
--- a/src/solver/solver_pool.cpp
+++ b/src/solver/solver_pool.cpp
@@ -399,7 +399,7 @@ solver* solver_pool::mk_solver() {
     }
     else {
         solver* s = m_solvers[(m_current_pool++) % m_num_pools];
-        base_solver = dynamic_cast<pool_solver*>(s)->base_solver();
+        base_solver = static_cast<pool_solver*>(s)->base_solver();
     }
     std::stringstream name;
     name << "vsolver#" << m_solvers.size();
@@ -412,7 +412,7 @@ solver* solver_pool::mk_solver() {
 void solver_pool::reset_solver(solver* s) {
     pool_solver* ps = dynamic_cast<pool_solver*>(s);
     SASSERT(ps);
-    if (ps) ps->reset();
+    ps->reset();
 }
 
 void solver_pool::refresh(solver* base_solver) {
diff --git a/src/util/hashtable.h b/src/util/hashtable.h
index acbe2a818..70f0d7085 100644
--- a/src/util/hashtable.h
+++ b/src/util/hashtable.h
@@ -406,8 +406,7 @@ public:
     }
 
     void insert(const data & e) {
-        data tmp(e);
-        insert(std::move(tmp));
+        insert(data(e));
     }
 
 #define INSERT_LOOP_CORE_BODY() {                                               \
@@ -463,8 +462,7 @@ public:
     }
 
     bool insert_if_not_there_core(const data & e, entry * & et) {
-        data temp(e);
-        return insert_if_not_there_core(std::move(temp), et);
+        return insert_if_not_there_core(data(e), et);
     }
 
     /**
diff --git a/src/util/obj_hashtable.h b/src/util/obj_hashtable.h
index ad347f8e6..36715facf 100644
--- a/src/util/obj_hashtable.h
+++ b/src/util/obj_hashtable.h
@@ -57,19 +57,7 @@ class obj_map {
 public:
     struct key_data {
         Key *  m_key = nullptr;
-        Value  m_value{};
-        key_data() = default;
-        key_data(Key * k):
-            m_key(k) {
-        }
-        key_data(Key * k, Value const & v):
-            m_key(k),
-            m_value(v) {
-        }
-        key_data(Key * k, Value && v) :
-            m_key(k),
-            m_value(std::move(v)) {
-        }
+        Value  m_value;
         Value const & get_value() const { return m_value; }
         Key & get_key () const { return *m_key; }
         unsigned hash() const { return m_key->hash(); }
@@ -97,8 +85,8 @@ public:
     table m_table;
   
 public:
-    obj_map():
-        m_table(DEFAULT_HASHTABLE_INITIAL_CAPACITY) {}
+    obj_map(unsigned initial_capacity = DEFAULT_HASHTABLE_INITIAL_CAPACITY):
+        m_table(initial_capacity) {}
     
     typedef typename table::iterator iterator;
     typedef typename table::data data;
@@ -146,6 +134,10 @@ public:
         return m_table.insert_if_not_there2(key_data(k, v))->get_data().m_value;
     }
 
+    bool insert_if_not_there_core(Key * k, Value const & v, obj_map_entry * & et) {
+        return m_table.insert_if_not_there_core({k, v}, et);
+    }
+
     obj_map_entry * insert_if_not_there3(Key * k, Value const & v) {
         return m_table.insert_if_not_there2(key_data(k, v));
     }