diff --git a/jbmc/src/java_bytecode/replace_java_nondet.cpp b/jbmc/src/java_bytecode/replace_java_nondet.cpp
index c02ae91bdd8..1ad46ecebd8 100644
--- a/jbmc/src/java_bytecode/replace_java_nondet.cpp
+++ b/jbmc/src/java_bytecode/replace_java_nondet.cpp
@@ -92,11 +92,10 @@ get_nondet_instruction_info(const goto_programt::const_targett &instr)
   {
     return nondet_instruction_infot();
   }
-  const auto &code = to_code(instr->code);
-  if(code.get_statement() != ID_function_call)
-  {
-    return nondet_instruction_infot();
-  }
+  const auto &code = instr->code;
+  INVARIANT(
+    code.get_statement() == ID_function_call,
+    "function_call should have ID_function_call");
   const auto &function_call = to_code_function_call(code);
   return is_nondet_returning_object(function_call);
 }
diff --git a/src/analyses/flow_insensitive_analysis.cpp b/src/analyses/flow_insensitive_analysis.cpp
index ce55e807979..b9fe025a203 100644
--- a/src/analyses/flow_insensitive_analysis.cpp
+++ b/src/analyses/flow_insensitive_analysis.cpp
@@ -40,19 +40,13 @@ exprt flow_insensitive_abstract_domain_baset::get_guard(
 exprt flow_insensitive_abstract_domain_baset::get_return_lhs(locationt to) const
 {
   // get predecessor of "to"
-
   to--;
 
   if(to->is_end_function())
     return static_cast<const exprt &>(get_nil_irep());
 
   // must be the function call
-  assert(to->is_function_call());
-
-  const code_function_callt &code=
-    to_code_function_call(to_code(to->code));
-
-  return code.lhs();
+  return to_code_function_call(to->code).lhs();
 }
 
 void flow_insensitive_analysis_baset::operator()(
@@ -164,8 +158,7 @@ bool flow_insensitive_analysis_baset::visit(
     if(l->is_function_call())
     {
       // this is a big special case
-      const code_function_callt &code=
-        to_code_function_call(to_code(l->code));
+      const code_function_callt &code = to_code_function_call(l->code);
 
       changed=
         do_function_call_rec(
@@ -213,8 +206,7 @@ bool flow_insensitive_analysis_baset::do_function_call(
 
   if(!goto_function.body_available())
   {
-    const code_function_callt &code =
-      to_code_function_call(to_code(l_call->code));
+    const code_function_callt &code = to_code_function_call(l_call->code);
 
     goto_programt temp;
 
diff --git a/src/ansi-c/c_typecheck_code.cpp b/src/ansi-c/c_typecheck_code.cpp
index a591883ad24..a2656486686 100644
--- a/src/ansi-c/c_typecheck_code.cpp
+++ b/src/ansi-c/c_typecheck_code.cpp
@@ -626,7 +626,7 @@ void c_typecheck_baset::typecheck_ifthenelse(code_ifthenelset &code)
 
   implicit_typecast_bool(cond);
 
-  if(to_code(code.then_case()).get_statement()==ID_decl_block)
+  if(code.then_case().get_statement() == ID_decl_block)
   {
     code_blockt code_block;
     code_block.add_source_location()=code.then_case().source_location();
@@ -635,11 +635,11 @@ void c_typecheck_baset::typecheck_ifthenelse(code_ifthenelset &code)
     code.then_case().swap(code_block);
   }
 
-  typecheck_code(to_code(code.then_case()));
+  typecheck_code(code.then_case());
 
   if(!code.else_case().is_nil())
   {
-    if(to_code(code.else_case()).get_statement()==ID_decl_block)
+    if(code.else_case().get_statement() == ID_decl_block)
     {
       code_blockt code_block;
       code_block.add_source_location()=code.else_case().source_location();
@@ -648,7 +648,7 @@ void c_typecheck_baset::typecheck_ifthenelse(code_ifthenelset &code)
       code.else_case().swap(code_block);
     }
 
-    typecheck_code(to_code(code.else_case()));
+    typecheck_code(code.else_case());
   }
 }
 
diff --git a/src/ansi-c/expr2c.cpp b/src/ansi-c/expr2c.cpp
index d1bf4d069e5..2f91ac42e00 100644
--- a/src/ansi-c/expr2c.cpp
+++ b/src/ansi-c/expr2c.cpp
@@ -2593,9 +2593,9 @@ std::string expr2ct::convert_code_ifthenelse(
     dest+=';';
   }
   else
-    dest+=convert_code(
-        to_code(src.then_case()),
-        to_code(src.then_case()).get_statement()==ID_block ? indent : indent+2);
+    dest += convert_code(
+      src.then_case(),
+      src.then_case().get_statement() == ID_block ? indent : indent + 2);
   dest+="\n";
 
   if(!src.else_case().is_nil())
@@ -2603,9 +2603,9 @@ std::string expr2ct::convert_code_ifthenelse(
     dest+="\n";
     dest+=indent_str(indent);
     dest+="else\n";
-    dest+=convert_code(
-        to_code(src.else_case()),
-        to_code(src.else_case()).get_statement()==ID_block ? indent : indent+2);
+    dest += convert_code(
+      src.else_case(),
+      src.else_case().get_statement() == ID_block ? indent : indent + 2);
   }
 
   return dest;
diff --git a/src/goto-instrument/goto_program2code.cpp b/src/goto-instrument/goto_program2code.cpp
index 9694c2781d1..5f8a4b00c74 100644
--- a/src/goto-instrument/goto_program2code.cpp
+++ b/src/goto-instrument/goto_program2code.cpp
@@ -1117,17 +1117,17 @@ goto_programt::const_targett goto_program2codet::convert_goto_if(
   if(has_else)
   {
     for(++target; target!=before_else; ++target)
-      target=convert_instruction(target, before_else, to_code(i.then_case()));
+      target = convert_instruction(target, before_else, i.then_case());
 
-    convert_labels(before_else, to_code(i.then_case()));
+    convert_labels(before_else, i.then_case());
 
     for(++target; target!=end_if; ++target)
-      target=convert_instruction(target, end_if, to_code(i.else_case()));
+      target = convert_instruction(target, end_if, i.else_case());
   }
   else
   {
     for(++target; target!=end_if; ++target)
-      target=convert_instruction(target, end_if, to_code(i.then_case()));
+      target = convert_instruction(target, end_if, i.then_case());
   }
 
   dest.move_to_operands(i);
@@ -1354,12 +1354,12 @@ goto_programt::const_targett goto_program2codet::convert_start_thread(
 
   // use pthreads if "code in new thread" is a function call to a function with
   // suitable signature
-  if(thread_start->is_function_call() &&
-     to_code_function_call(to_code(thread_start->code)).arguments().size()==1 &&
-     after_thread_start==thread_end)
+  if(
+    thread_start->is_function_call() &&
+    to_code_function_call(thread_start->code).arguments().size() == 1 &&
+    after_thread_start == thread_end)
   {
-    const code_function_callt &cf=
-      to_code_function_call(to_code(thread_start->code));
+    const code_function_callt &cf = to_code_function_call(thread_start->code);
 
     system_headers.insert("pthread.h");
 
@@ -1730,14 +1730,15 @@ void goto_program2codet::cleanup_code_ifthenelse(
 
   // assert(false) expands to if(true) assert(false), simplify again (and also
   // simplify other cases)
-  if(cond.is_true() &&
-      (i_t_e.else_case().is_nil() || !has_labels(to_code(i_t_e.else_case()))))
+  if(
+    cond.is_true() &&
+    (i_t_e.else_case().is_nil() || !has_labels(i_t_e.else_case())))
   {
     codet tmp;
     tmp.swap(i_t_e.then_case());
     code.swap(tmp);
   }
-  else if(cond.is_false() && !has_labels(to_code(i_t_e.then_case())))
+  else if(cond.is_false() && !has_labels(i_t_e.then_case()))
   {
     if(i_t_e.else_case().is_nil())
       code=code_skipt();
@@ -1750,8 +1751,9 @@ void goto_program2codet::cleanup_code_ifthenelse(
   }
   else
   {
-    if(i_t_e.then_case().is_not_nil() &&
-       to_code(i_t_e.then_case()).get_statement()==ID_ifthenelse)
+    if(
+      i_t_e.then_case().is_not_nil() &&
+      i_t_e.then_case().get_statement() == ID_ifthenelse)
     {
       // we re-introduce 1-code blocks with if-then-else to avoid dangling-else
       // ambiguity
@@ -1760,9 +1762,10 @@ void goto_program2codet::cleanup_code_ifthenelse(
       i_t_e.then_case().swap(b);
     }
 
-    if(i_t_e.else_case().is_not_nil() &&
-       to_code(i_t_e.then_case()).get_statement()==ID_skip &&
-       to_code(i_t_e.else_case()).get_statement()==ID_ifthenelse)
+    if(
+      i_t_e.else_case().is_not_nil() &&
+      i_t_e.then_case().get_statement() == ID_skip &&
+      i_t_e.else_case().get_statement() == ID_ifthenelse)
     {
       // we re-introduce 1-code blocks with if-then-else to avoid dangling-else
       // ambiguity
@@ -1795,8 +1798,9 @@ void goto_program2codet::cleanup_code_ifthenelse(
   }
 
   // remove empty then/else
-  if(code.get_statement()==ID_ifthenelse &&
-      to_code(i_t_e.then_case()).get_statement()==ID_skip)
+  if(
+    code.get_statement() == ID_ifthenelse &&
+    i_t_e.then_case().get_statement() == ID_skip)
   {
     not_exprt tmp(i_t_e.cond());
     simplify(tmp, ns);
@@ -1805,15 +1809,15 @@ void goto_program2codet::cleanup_code_ifthenelse(
     i_t_e.cond().swap(tmp);
     i_t_e.then_case().swap(i_t_e.else_case());
   }
-  if(code.get_statement()==ID_ifthenelse &&
-      i_t_e.else_case().is_not_nil() &&
-      to_code(i_t_e.else_case()).get_statement()==ID_skip)
+  if(
+    code.get_statement() == ID_ifthenelse && i_t_e.else_case().is_not_nil() &&
+    i_t_e.else_case().get_statement() == ID_skip)
     i_t_e.else_case().make_nil();
   // or even remove the if altogether if the then case is now empty
-  if(code.get_statement()==ID_ifthenelse &&
-      i_t_e.else_case().is_nil() &&
-      (i_t_e.then_case().is_nil() ||
-       to_code(i_t_e.then_case()).get_statement()==ID_skip))
+  if(
+    code.get_statement() == ID_ifthenelse && i_t_e.else_case().is_nil() &&
+    (i_t_e.then_case().is_nil() ||
+     i_t_e.then_case().get_statement() == ID_skip))
     code=code_skipt();
 }
 
diff --git a/src/goto-programs/goto_convert.cpp b/src/goto-programs/goto_convert.cpp
index a2a626f38dd..b9259cbe9a6 100644
--- a/src/goto-programs/goto_convert.cpp
+++ b/src/goto-programs/goto_convert.cpp
@@ -1569,12 +1569,12 @@ void goto_convertt::convert_ifthenelse(
 
   // convert 'then'-branch
   goto_programt tmp_then;
-  convert(to_code(code.then_case()), tmp_then, mode);
+  convert(code.then_case(), tmp_then, mode);
 
   goto_programt tmp_else;
 
   if(has_else)
-    convert(to_code(code.else_case()), tmp_else, mode);
+    convert(code.else_case(), tmp_else, mode);
 
   exprt tmp_guard=code.cond();
   clean_expr(tmp_guard, dest, mode);
diff --git a/src/goto-programs/remove_unused_functions.cpp b/src/goto-programs/remove_unused_functions.cpp
index fbb4d9d5947..85cb1e3364c 100644
--- a/src/goto-programs/remove_unused_functions.cpp
+++ b/src/goto-programs/remove_unused_functions.cpp
@@ -75,8 +75,7 @@ void find_used_functions(
       {
         if(it->type==FUNCTION_CALL)
         {
-          const code_function_callt &call =
-            to_code_function_call(to_code(it->code));
+          const code_function_callt &call = to_code_function_call(it->code);
 
           // check that this is actually a simple call
           assert(call.function().id()==ID_symbol);
diff --git a/src/goto-symex/memory_model_tso.cpp b/src/goto-symex/memory_model_tso.cpp
index 8bf28a28813..32551d53bc1 100644
--- a/src/goto-symex/memory_model_tso.cpp
+++ b/src/goto-symex/memory_model_tso.cpp
@@ -107,7 +107,7 @@ void memory_model_tsot::program_order(
 
         if((*e_it2)->is_memory_barrier())
         {
-          const codet &code=to_code((*e_it2)->source.pc->code);
+          const codet &code = (*e_it2)->source.pc->code;
 
           if((*e_it)->is_shared_read() &&
              !code.get_bool(ID_RRfence) &&
diff --git a/src/goto-symex/symex_dead.cpp b/src/goto-symex/symex_dead.cpp
index a6654c99409..ee6c582bf5f 100644
--- a/src/goto-symex/symex_dead.cpp
+++ b/src/goto-symex/symex_dead.cpp
@@ -21,7 +21,7 @@ void goto_symext::symex_dead(statet &state)
 {
   const goto_programt::instructiont &instruction=*state.source.pc;
 
-  const codet &code=to_code(instruction.code);
+  const codet &code = instruction.code;
 
   if(code.operands().size()!=1)
     throw "dead expects one operand";
diff --git a/src/goto-symex/symex_decl.cpp b/src/goto-symex/symex_decl.cpp
index 776f8ddd2ed..2961684a3fc 100644
--- a/src/goto-symex/symex_decl.cpp
+++ b/src/goto-symex/symex_decl.cpp
@@ -23,7 +23,7 @@ void goto_symext::symex_decl(statet &state)
 {
   const goto_programt::instructiont &instruction=*state.source.pc;
 
-  const codet &code=to_code(instruction.code);
+  const codet &code = instruction.code;
 
   if(code.operands().size()==2)
     throw "two-operand decl not supported here";
diff --git a/src/goto-symex/symex_other.cpp b/src/goto-symex/symex_other.cpp
index c1ceff5c12d..b6f62d2dcd6 100644
--- a/src/goto-symex/symex_other.cpp
+++ b/src/goto-symex/symex_other.cpp
@@ -78,7 +78,7 @@ void goto_symext::symex_other(
 {
   const goto_programt::instructiont &instruction=*state.source.pc;
 
-  const codet &code=to_code(instruction.code);
+  const codet &code = instruction.code;
 
   const irep_idt &statement=code.get_statement();
 
diff --git a/src/jsil/jsil_typecheck.cpp b/src/jsil/jsil_typecheck.cpp
index 36393c73af6..f0628ea8a0e 100644
--- a/src/jsil/jsil_typecheck.cpp
+++ b/src/jsil/jsil_typecheck.cpp
@@ -832,10 +832,10 @@ void jsil_typecheckt::typecheck_ifthenelse(code_ifthenelset &code)
   typecheck_expr(cond);
   make_type_compatible(cond, bool_typet(), true);
 
-  typecheck_code(to_code(code.then_case()));
+  typecheck_code(code.then_case());
 
   if(!code.else_case().is_nil())
-    typecheck_code(to_code(code.else_case()));
+    typecheck_code(code.else_case());
 }
 
 void jsil_typecheckt::typecheck_assign(code_assignt &code)
diff --git a/src/pointer-analysis/goto_program_dereference.cpp b/src/pointer-analysis/goto_program_dereference.cpp
index 063af881e52..f8a395f5246 100644
--- a/src/pointer-analysis/goto_program_dereference.cpp
+++ b/src/pointer-analysis/goto_program_dereference.cpp
@@ -307,7 +307,7 @@ void goto_program_dereferencet::dereference_instruction(
   }
   else if(i.is_function_call())
   {
-    code_function_callt &function_call=to_code_function_call(to_code(i.code));
+    code_function_callt &function_call = to_code_function_call(i.code);
 
     if(function_call.lhs().is_not_nil())
       dereference_expr(