Having problem with implementing a chain class (chaining two containers) - c++

Question

I wrote a 'range-class' (get as input start and end index) and output all elements between them (int, char, double etc.)
I have a problem implementing the 'chain-class', chain takes two containers (a range class or a string) and chain it.The problem is that the begin and end class doesn't recognize the inner class type.
Range class implementation:
template<typename T>
struct RangeClass{
T start, last;
RangeClass(T first, T last): start(first), last(last) { };
struct iterator{ //inner class
T it;
T operator* (){ return it;
iterator& operator++() { ++it; return *this; }
bool operator== (const iterator& other){ return it==other.it; }
bool operator!= (const iterator& other){ return it!=other.it; }
}; // end Iterator
iterator end() const{ return iterator{last}
iterator begin() const{ return iterator{start};}
}; // end RangeClass
template<typename T>
RangeClass<T> range(T first, T last){
return RangeClass(first, last);
}
The ChainClass is:
template <typename T, typename V>
struct ChainRanges{
T t1;
V v1;
ChainRanges (const T& first, const V& second):
t1(first), v1(second)
{}
template<typename Y>
struct iterator{
Y var;
Y operator* (){ return var; }
iterator& operator++(){//right? can access outer class fields?
if(var==*it.end())
var=*v1.begin();
else
++var;
bool operator== (const iterator& other){ return var==other.var; }
bool operator!= (const oiterator& other){ return var!=other.var; }
}; // end Iterator
auto end() const {
//auto? or iterator<Y>
auto var = ( *(v1.end()) ) ;
return iterator{var};
}
auto begin() const{
auto var = ( *(t1.begin()) ) ;
return iterator{var};
}
}; // end struct chain
template<typename T, typename V>
ChainRanges<T,V >
chain(T first, V second)
{
return ChainRanges(first, second);
}
Main is :
for (int i: range(5,9))
cout << i; //prints 5678
for (char i: chain(range('a','e'), string("hello")))
cout << i;//want this to work = // abcdhello

Answer 1

No you cannot access outer class fields. Subclasses have friend-style access, but no state access, to their outer class. Of you want a pointer to their outer class you have to add one.
Values have fixed types in C++. You cannot have an.iterator value of two.possible types.
You can have a pointer to two possible types if they share a basr class. You can use type erasure to wrap multiple types into one variable. You can use std variant, std any, void pointers and careful manual vtables, concept and model templates wrapped by regular type abstractions, or a myriad of other ways to have "values.of more than one type"; they aren't really values of more than one type, just polymorphic behaviour values that include some type aware dispatching code.
Templates are not inheritly runtime polymorphic in C++, unlike Generics in Java/C#. Templates generate types and functions. The generated types and functions are unrelated at runtime, unless of course you make them related.
There are piles of ways to solve your problem, from boost any iterator to fun type manual type erasing the concept of iterable and printable, or print-iterable even. I know of none that you'd be wise to try at your level of C++ expertise.