Re: Reference assignment through base class reference
On Jun 4, 10:49 pm, siddhu <siddharth....@gmail.com> wrote:
#include <stdio.h>
class Base
{};
class Der1:public Base
{
};
class Der2:public Base
{
};
int main()
{
Der1 d1;Der2 d2;
Base& b1 = d1;
Base& b2 = d2;
b1 = b2;
}
Above code gets compiled. But I wonder what does the
assignment b1 = b2; do?
Nothing useful. It assigns the Base part of d2 to the Base part
of d1.
If these are pointers then its understandable. But how does
above assignment behave in case of references. Does it exhibit UB?
Not directly. Of course, class invariants are likely broken,
but that's not a language problem---the language specifies a
behavior here.
In general, assignment doesn't work well with polymorphic
objects. Typically, if a class is designed to be used as a
base, it will have a private assignment operator, so that such
code will be illegal.
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