working example -> tested on shell C++

CPP/register_modeling/example_project/problem_test.txt

@@ -34,22 +34,17 @@ struct BitField
     BitField& operator =(T v)
     {
 
-/*
-        // this step can be optimised for systems that support bitbandalias 
-        T mask = ((1ULL << SIZE)-1) << START;
-        _raw &= ~mask;
-        _raw |= ((v & ((1ULL << SIZE)-1)) << START);
+#if 0
+        _raw = ((v & ((1ULL << SIZE)-1)) << START);
         return *this;
-        */
-
-
+#else
+        //_raw & ~(((1ULL << SIZE)-1) << START);
         
-        //#ifdef old
-        //TODO: test = problem with |= instead of =
-        // mask creation for v : https://stackoverflow.com/questions/1392059/algorithm-to-generate-bit-mask
+        // use bit band alias if system permits
         _raw = ((v & ((1ULL << SIZE)-1)) << START) | (_raw & ~(((1ULL << SIZE)-1) << START));
         return *this;
         //#endif
+#endif
     }
     
     /**
@@ -80,18 +75,18 @@ union Reg_Control
 {
     // bit 4
     struct POWER_DEV{
-                typedef BitField<uint8_t, 4, 1> Bits;
+        typedef BitField<uint8_t, 7, 1> Bits;
         enum{TURN_OFF = 0, TURN_ON = 1};
     };
     // bits 2-3
     struct SPEED{
-                typedef BitField<uint8_t, 2, 2> Bits;
+        typedef BitField<uint8_t, 0, 2> Bits;
         enum{STAND_STILL = 0,
              SLOW = 1,
              NORMAL = 2,
              FAST = 3};
     };
-            struct Bits{
+    union Bits{
         Reg_Control::POWER_DEV::Bits POWER_DEV;
         Reg_Control::SPEED::Bits SPEED;
     } bits;
@@ -107,15 +102,23 @@ int main()
 {
     Reg_Control reg;
     
-    reg.bits.SPEED = Reg_Control::SPEED::FAST;
+    //reg.bits.SPEED = Reg_Control::SPEED::FAST;
     reg.bits.POWER_DEV = Reg_Control::POWER_DEV::TURN_ON;
     
     
     std::cout << +reg.raw << std::endl;
     
     reg.bits.POWER_DEV = Reg_Control::POWER_DEV::TURN_OFF;
+    
+    std::cout << +reg.raw << std::endl;
+    
+    reg.bits.POWER_DEV = Reg_Control::POWER_DEV::TURN_ON;
     reg.bits.SPEED = Reg_Control::SPEED::SLOW;
     
+    std::cout << +reg.raw << std::endl;
+    
+    reg.bits.POWER_DEV = Reg_Control::POWER_DEV::TURN_OFF;
+    reg.bits.SPEED = Reg_Control::SPEED::FAST;
     
     std::cout << +reg.raw << std::endl;