add utilities in xfor.h + fix SIZE in SubExpr

src/include/xfor/iloop.h

@@ -13,6 +13,13 @@ namespace MultiArrayHelper
     template <size_t N>
     struct NN
     {
+        template <class LTp>
+        static inline constexpr size_t LSIZE()
+        {
+            typedef typename std::tuple_element<N,LTp>::type LType;
+            return LType::SIZE + NN<N-1>::template LSIZE<LTp>();
+        }
+        
         template <class LTp>
         static inline constexpr size_t lsize(const LTp& ltp)
         {
@@ -50,6 +57,13 @@ namespace MultiArrayHelper
     template <>
     struct NN<0>
     {
+        template <class LTp>
+        static inline constexpr size_t LSIZE()
+        {
+            typedef typename std::tuple_element<0,LTp>::type LType;
+            return LType::SIZE;
+        }
+
         template <class LTp>
         static inline constexpr size_t lsize(const LTp& ltp)
         {
@@ -99,7 +113,8 @@ namespace MultiArrayHelper
         std::array<size_t,VarTpSize> mSetzero; // set variable to zero after each cycle
             
     public:
-        static constexpr size_t SIZE = NN<LTpSize-1>::lsize(std::declval<LTp>());
+        //static constexpr size_t SIZE = NN<LTpSize-1>::lsize(std::declval<LTp>());
+        static constexpr size_t SIZE = NN<LTpSize-1>::template LSIZE<LTp>();
         static constexpr bool CONT = false;
         typedef decltype(NN<LTpSize-1>::rootSteps(mLTp)) ExtType;
 
@@ -123,6 +138,10 @@ namespace MultiArrayHelper
             return NN<LTpSize-1>::rootSteps(mLTp,i);
         }
 
+        VarTp& var() const
+        {
+            return mVarTp;
+        }
     };
 
     template <size_t N>
@@ -237,6 +256,10 @@ namespace MultiArrayHelper
             return mL.rootSteps(i);
         }
 
+        auto var() const
+        {
+            return mL.var();
+        }
     };
 
 }

src/include/xfor/xfor.h

@@ -161,7 +161,7 @@ namespace MultiArrayHelper
 	typedef ExpressionBase EB;
 	
 	static constexpr size_t LAYER = Expr::LAYER + 1;
-	static constexpr size_t SIZE = Expr::SIZE;
+	static constexpr size_t SIZE = Expr::SIZE + 1;
 
 	SubExpr(const SubExpr& in) = default;
 	SubExpr& operator=(const SubExpr& in) = default;