Why can const char* const & = “hello” compile?

Question

I am reading a code snippet from a book and find this:

const char* const & a = \"hello\"; //can compile 
const char*& a = \"hello\"; //cannot
         


        

Answer 1

It's essentially adhering to this formula

T const & a = something_convertible_to_T;

Where T is const char*. In the first case, a temporary pointer can be materialized, assigned the address of the literal, and then have itself bound to the reference. In the second case, since the lvalue reference isn't const, it can't happen. Another example of more of the same

const char* && a = "hello"; // rvalue ref makes a no into a yes.

Now the temporary pointer is bound to an rvalue reference.