accessing variables from an intended block of nested blocks [duplicate]

Answer 1

Use references.

// Block A
int aa = 30;
auto& ref_aa = aa;
{
    // Block B
    int aa = 40;

    {
        // Block C
        int aa = 50;

        cout << "block C " << aa << endl;
        cout << "block A " << ref_aa << endl;
        cout << "global" << ::aa << endl;
    }

    cout << "block B " << aa << endl;
}

Of course, that's quite meaningless; if you can modify the code, then just change the variable names, or refactor it such that fewer blocks are needed (using more functions, for example).