various improvements regarding static pos evaluation

src/include/ranges/lindex.cc.h

@@ -49,8 +49,14 @@ namespace CNORXZ
     template <class Xpr, class F>
     decltype(auto) LIndex<Index,L>::ifor(const Xpr& xpr, F&& f) const
     {
+	if constexpr(index_has_const_size<Index>::value){
+	    constexpr SizeT S = index_const_size<Index>::value;
+	    return SFor<S,L,Xpr,F>(this->id(), xpr, std::forward<F>(f));
+	}
+	else {
 	    return For<L,Xpr,F>(this->pmax().val(), this->id(), xpr, std::forward<F>(f));
 	}
+    }
     
     template <class Index, SizeT L, class I1>
     decltype(auto) operator*(const Sptr<LIndex<Index,L>>& a, const Sptr<I1>& b)

src/include/ranges/srange.h

@@ -247,6 +247,22 @@ namespace CNORXZ
     {
 	static constexpr bool value = true;
     };
+
+    /** ***
+	SIndex has static range size
+	@see index_expression_exists
+     */    
+    template <typename MetaT, SizeT S>
+    struct index_has_const_size<SIndex<MetaT,S>>
+    { static constexpr bool value = true; };
+
+    /** ***
+	SIndex has static range size
+	@see index_expression_exists
+     */    
+    template <typename MetaT, SizeT S>
+    struct index_const_size<SIndex<MetaT,S>>
+    { static constexpr SizeT value = S; };
 }
 
 #endif

src/include/xpr/pos_type.cc.h

@@ -480,13 +480,19 @@ namespace CNORXZ
 	return mNext;
     }
 
+    template <class BPosT, class NPosT>
+    constexpr const BPosT& MPos<BPosT,NPosT>::bpos() const
+    {
+	return *this;
+    }
+
     template <class BPosT, class NPosT>
     template <class PosT>
     constexpr decltype(auto) MPos<BPosT,NPosT>::operator+(const PosT& a) const
     {
-	typedef decltype(BPosT::operator+(a)) OBPosT;
+	typedef decltype(BPosT::operator+(a.bpos())) OBPosT;
 	typedef decltype(mNext + a.next()) ONPosT;
-	return MPos<OBPosT,ONPosT>( BPosT::operator+(a), mNext + a.next() );
+	return MPos<OBPosT,ONPosT>( BPosT::operator+(a.bpos()), mNext + a.next() );
     }
 
     template <class BPosT, class NPosT>

src/include/xpr/pos_type.h

@@ -177,6 +177,7 @@ namespace CNORXZ
 
 	constexpr SizeT size() const;
 	constexpr const NPosT& next() const;
+	constexpr const BPosT& bpos() const;
 
 	template <class PosT>
 	constexpr decltype(auto) operator+(const PosT& a) const;