add meta position access (compiles, untested)

src/multi_range.cc

@@ -224,6 +224,52 @@ namespace MultiArrayTools
 	    }
 	};
 
+	template <size_t N>
+	struct MetaPosGetter
+	{
+	    template <class... Indices>
+	    static void getMetaPos(typename MultiIndex<Indices...>::MetaType& target,
+				   const typename MultiIndex<Indices...>::IndexPack& source)
+	    {
+		std::get<N>(target) = std::get<N>(source).getMetaPos();
+		MetaPosGetter<N-1>::getMetaPos(target, source);
+	    }
+	};
+
+	template <>
+	struct MetaPosGetter<0>
+	{
+	    template <class... Indices>
+	    static void getMetaPos(typename MultiIndex<Indices...>::MetaType& target,
+				   const typename MultiIndex<Indices...>::IndexPack& source)
+	    {
+		std::get<0>(target) = std::get<0>(source).getMetaPos();
+	    }
+	};
+
+	template <size_t N>
+	struct MetaSetter
+	{
+	    template <class... Indices>
+	    static void setMeta(typename MultiIndex<Indices...>::IndexPack& target,
+				const typename MultiIndex<Indices...>::MetaType& source)
+	    {
+		std::get<N>(target).atMeta( std::get<N>(source) );
+		MetaSetter<N-1>::setMeta(target, source);
+	    }
+	};
+
+	template <>
+	struct MetaSetter<0>
+	{
+	    template <class... Indices>
+	    static void setMeta(typename MultiIndex<Indices...>::IndexPack& target,
+				const typename MultiIndex<Indices...>::MetaType& source)
+	    {
+		std::get<0>(target).atMeta( std::get<0>(source) );
+	    }
+	};
+	
     }
 
     template <class... Indices>
@@ -445,6 +491,7 @@ namespace MultiArrayTools
     IndefinitIndexBase& MultiIndex<Indices...>::get(size_t n)
     {
 	if(n >= sizeof...(Indices)){
+	    assert(0);
 	    // throw !!
 	}
 	MultiIndex<Indices...>* t = this;
@@ -455,12 +502,28 @@ namespace MultiArrayTools
     const IndefinitIndexBase& MultiIndex<Indices...>::get(size_t n) const
     {
 	if(n >= sizeof...(Indices)){
+	    assert(0);
 	    // throw !!
 	}
 	MultiIndex<Indices...> const* t = this;
 	return IndexGetter<sizeof...(Indices)-1>::getIndex(*t, n);
     }
 
+    template <class... Indices>
+    typename MultiIndex<Indices...>::MetaType MultiIndex<Indices...>::getMetaPos() const
+    {
+        MetaType metaTuple;
+	MetaPosGetter<sizeof...(Indices)-1>::getMetaPos(metaTuple, mIPack);
+	return metaTuple;
+    }
+
+    template <class... Indices>
+    MultiIndex<Indices...>& MultiIndex<Indices...>::atMeta(const MultiIndex<Indices...>::MetaType& metaPos)
+    {
+	MetaSetter<sizeof...(Indices)-1>::setMeta(mIPack, metaPos);
+	return *this;
+    }
+
     template <class... Indices>
     bool MultiIndex<Indices...>::linkLower(IndefinitIndexBase* toLink)
     {

src/multi_range.h

@@ -20,6 +20,7 @@ namespace MultiArrayTools
 	typedef std::tuple<Indices...> IndexPack;
 	typedef IndefinitIndexBase IIB;
 	typedef IndexBase<MultiIndex<Indices...> > IB;
+	typedef std::tuple<decltype(Indices().getMetaPos())...> MetaType;
 	
     protected:
 	
@@ -67,6 +68,9 @@ namespace MultiArrayTools
 	IndefinitIndexBase& get(size_t n);
 	const IndefinitIndexBase& get(size_t n) const;
 
+        MetaType getMetaPos() const;
+	MultiIndex& atMeta(const MetaType& metaPos);
+	
 	MultiIndex& operator()(Indices&&... inds);
 	MultiIndex& operator()(const Indices&... inds);
 	

src/single_range.cc

@@ -18,7 +18,7 @@ namespace MultiArrayTools
     }
 
     template <typename U, RangeType TYPE>
-    size_t SingleRange<U,TYPE>::get(const U& metaPos) const
+    size_t SingleRange<U,TYPE>::getMeta(const U& metaPos) const
     {
 	size_t cnt = 0;
 	for(auto& x: mSpace){
@@ -131,6 +131,13 @@ namespace MultiArrayTools
 	return dynamic_cast<SingleRange<U,TYPE> const*>( IB::mRange )->get(IIB::pos());
     }
 
+    template <typename U, RangeType TYPE>
+    SingleIndex<U,TYPE>& SingleIndex<U,TYPE>::atMeta(const U& metaPos)
+    {
+	operator=( dynamic_cast<SingleRange<U,TYPE> const*>( IB::mRange )->getMeta(metaPos) );
+	return *this;
+    }
+
     template <typename U, RangeType TYPE>
     size_t SingleIndex<U,TYPE>::dim() const
     {

src/single_range.h

@@ -44,6 +44,7 @@ namespace MultiArrayTools
 	virtual MultiRangeType rangeType() const override;
 
 	virtual const U& getMetaPos() const;
+	virtual SingleIndex& atMeta(const U& metaPos);
 	
 	virtual size_t dim() const override; // = 1
 	virtual void linkTo(IndefinitIndexBase* target) override;
@@ -68,7 +69,7 @@ namespace MultiArrayTools
 	virtual size_t size() const override;
 	
 	const U& get(size_t pos) const;
-	size_t get(const U& metaPos) const;
+	size_t getMeta(const U& metaPos) const;
 
 	virtual MultiRangeType type() const override;