How can I create a polymorphic object on the stack?
c++, polymorphism, stack
Solution
You can't structure a single function to work like that, since automatic or temporary objects created inside a conditional block can't have their lifetimes extended into the containing block.
I'd suggest refactoring the polymorphic behaviour into a separate function:
void do_something(A&&);
switch (some_var)
{
case 1:
do_something(A());
break;
case 2:
do_something(B()); // B is derived from A
break;
default:
do_something(C()); // C is derived from A
break;
}
Problem
How do I allocate a polymorphic object on the stack? I'm trying to do something similar to (trying to avoid heap allocation with new)?: ``` A* a = NULL; switch (some_var) { case 1: a = A(); break; case 2: a = B(); // B is derived from A break; default: a = C(); // C is derived from A break; } ```