Storing a type in C++

Question

Is it possible to store a type name as a C++ variable? For example, like this:

type my_type = int; // or string, or Foo, or any other type
void* data = ...;
         


        

Answer 1

Today I had a similar problem while coding:
I had the need to store a polymoriphic data type (here named refobj) over wich call functions of the concrete classes implementing it. I need a solution that doesn't cast the variable explicitly because I need to reduce the amount of code.

My solution (but I haven't tested it yet) looks similar to a previous answer. Actually is quite an experimental solution. It look like this...

// interface to use in the function

class Type   
{
public:
    virtual void* getObj()const=0;
};

// here the static_cast with the "stored" type

template class TypeImpl : public Type
{
public:
    TypeImpl(T *obj) {myobj=obj;}
    virtual void* getObj()const{ return static_cast(myobj); }

private: 
    T* myobj;
};

// here the type that will contain the polimorific type
// that I don't want to cast explicitly in my code
Type *refobj;

// here the "user code "
void userofTypes()
{
    ( refobj->getObj() ).c_str(); 
    // getObj() should return a string type over which
    // calling string concrete functions ...let's try!
}

void main()
{
    refobj=new TypeImpl < string > ( new string("hello") );
    userofTypes();
}
// it might seem absurd don't cast refobj explicitly, but of
// course there are situation in which it can be useful!