reference a const reference

Hey all, I was just wondering why this won't compile.

Code:

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int a=5;
const int &b=a;
int &c=b;                //uh oh! why can't you reference a const ref?

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i mean, why not? what would be the problem if c changed? it only compiles if its constant.

thanks for the help

Well, consider this:

Code:

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const int b = 5;
int &c = b;

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If that compiled, then you could use c to change the (supposedly constant) value of b. Personally, I'm glad that the compiler won't let me do this. It keeps me from accidently changing a constant.

Code:

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int main() {
  int a;

  return f(a); // f accepts a const reference
                    // thus you can be sure a wont change with this function call
}


int f(const int &r_a) // const reference
{
  // fortunately this is not possible:
  int &b = r_a; // !!! if that was possible a could change - even you said in the function head that a wont change... thats a contradiction...
}

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if you could override "const" in such an easy way there would be no point in using const anyway...

of course. i forgot that references are implicit pointers. that was a pretty bad question. just goes to show what happens when you come back to c++ after a break :(