Move code into code block instead of copying it

Author: Owen Jones

src/ansi-c/c_nondet_symbol_factory.cpp

@@ -125,7 +125,7 @@ exprt symbol_factoryt::allocate_object(
   //   <target_expr> = &tmp$<temporary_counter>
   code_assignt assign(target_expr, aoe);
   assign.add_source_location()=loc;
-  assignments.add(assign);
+  assignments.move(assign);
 
   return aoe;
 }
@@ -186,7 +186,7 @@ void symbol_factoryt::gen_nondet_init(
       null_check.then_case()=set_null_inst;
       null_check.else_case()=non_null_inst;
 
-      assignments.add(null_check);
+      assignments.move(null_check);
     }
   }
   // TODO(OJones): Add support for structs and arrays
@@ -202,7 +202,7 @@ void symbol_factoryt::gen_nondet_init(
     code_assignt assign(expr, rhs);
     assign.add_source_location()=loc;
 
-    assignments.add(assign);
+    assignments.move(assign);
   }
 }
 
@@ -258,7 +258,7 @@ exprt c_nondet_symbol_factory(
   {
     code_declt decl(symbol_ptr->symbol_expr());
     decl.add_source_location()=loc;
-    init_code.add(decl);
+    init_code.move(decl);
   }
 
   init_code.append(assignments);
@@ -275,7 +275,7 @@ exprt c_nondet_symbol_factory(
         from_integer(0, index_type())));
     input_code.op1()=symbol_ptr->symbol_expr();
     input_code.add_source_location()=loc;
-    init_code.add(input_code);
+    init_code.move(input_code);
   }
 
   return main_symbol_expr;

src/util/std_code.h

@@ -78,6 +78,11 @@ class code_blockt:public codet
       o.push_back(*it);
   }
 
+  void move(codet &code)
+  {
+    move_to_operands(code);
+  }
+
   void add(const codet &code)
   {
     copy_to_operands(code);