Why is it illegal to take the address of an rvalue temporary?

Question

According to \" How to get around the warning "rvalue used as lvalue"? \", Visual Studio will merely warn on code such as this:

int bar() {
   retu         


        

Answer 1

Temporary objects do have memory. Sometimes the compiler creates temporaries as well. In poth cases these objects are about to go away, i.e. they shouldn't gather important changes by chance. Thus, you can get hold of a temporary only via an rvalue reference or a const reference but not via a non-const reference. Taking the address of an object which about to go away also feels like a dangerous thing and thus isn't supported.

If you are sure you really want a non-const reference or a pointer from a temporary object you can return it from a corresponding member function: you can call non-const member functions on temporaries. And you can return this from this member. However, note that the type system is trying to help you. When you trick it you better know that what you are diing is the Right Thing.