Ternary operator implicit cast to base class

Question

Consider this piece of code:

struct Base
{
    int x;
};

struct Bar : Base
{
    int y;
};

struct Foo : Base
{
    int z;
};

Bar* bar = new Bar;
Foo* foo          


        

Answer 1

In other words, why does Base* obj = foo; work without a cast but using the ?: operator doesn't?

The type of the conditional expression does not depend on the what it is assigned to. In your case, the compiler needs to be able to evaluate !bar ? foo : bar; regardless of what it is assigned to.

In your case, that is a problem since neither foo converted to type of bar nor bar can be converted to type of foo.

Is it because it's not clear that I want to use the Base part?

Precisely.