diff --git a/src/goto-programs/adjust_float_expressions.cpp b/src/goto-programs/adjust_float_expressions.cpp
index b66c12b32e4..25194e1ce3b 100644
--- a/src/goto-programs/adjust_float_expressions.cpp
+++ b/src/goto-programs/adjust_float_expressions.cpp
@@ -197,17 +197,16 @@ void adjust_float_expressions(
   goto_functionst::goto_functiont &goto_function,
   const namespacet &ns)
 {
-  Forall_goto_program_instructions(it, goto_function.body)
-  {
-    adjust_float_expressions(it->code, ns);
-
-    if(it->has_condition())
-    {
-      exprt c = it->get_condition();
-      adjust_float_expressions(c, ns);
-      it->set_condition(c);
-    }
-  }
+  for(auto &i : goto_function.body.instructions)
+    i.transform([&ns](exprt expr) -> optionalt<exprt> {
+      if(have_to_adjust_float_expressions(expr))
+      {
+        adjust_float_expressions(expr, ns);
+        return expr;
+      }
+      else
+        return {};
+    });
 }
 
 void adjust_float_expressions(
diff --git a/src/goto-programs/remove_complex.cpp b/src/goto-programs/remove_complex.cpp
index 9cf7a010b2e..e0a95651877 100644
--- a/src/goto-programs/remove_complex.cpp
+++ b/src/goto-programs/remove_complex.cpp
@@ -285,17 +285,16 @@ static void remove_complex(
 {
   remove_complex(goto_function.type);
 
-  Forall_goto_program_instructions(it, goto_function.body)
-  {
-    remove_complex(it->code);
-
-    if(it->has_condition())
-    {
-      exprt c = it->get_condition();
-      remove_complex(c);
-      it->set_condition(c);
-    }
-  }
+  for(auto &i : goto_function.body.instructions)
+    i.transform([](exprt e) -> optionalt<exprt> {
+      if(have_to_remove_complex(e))
+      {
+        remove_complex(e);
+        return e;
+      }
+      else
+        return {};
+    });
 }
 
 /// removes complex data type
diff --git a/src/goto-programs/remove_vector.cpp b/src/goto-programs/remove_vector.cpp
index 42b1601de06..7b4ff901909 100644
--- a/src/goto-programs/remove_vector.cpp
+++ b/src/goto-programs/remove_vector.cpp
@@ -219,17 +219,16 @@ void remove_vector(goto_functionst::goto_functiont &goto_function)
 {
   remove_vector(goto_function.type);
 
-  Forall_goto_program_instructions(it, goto_function.body)
-  {
-    remove_vector(it->code);
-
-    if(it->has_condition())
-    {
-      exprt c = it->get_condition();
-      remove_vector(c);
-      it->set_condition(c);
-    }
-  }
+  for(auto &i : goto_function.body.instructions)
+    i.transform([](exprt e) -> optionalt<exprt> {
+      if(have_to_remove_vector(e))
+      {
+        remove_vector(e);
+        return e;
+      }
+      else
+        return {};
+    });
 }
 
 /// removes vector data type