I made a booboo

Anyone know how to fix this lump of shit to reverse a text string?  Fffuuuck

#include <iostream>
#include <string>

using namespace std;

string reverse(string& str);

void writeBackward(string s, int size)
{
   if (size > 0)
   {  // write the last character
      cout << s.substr(size-1, 1);
 
      // write the rest of the string backward
      writeBackward(s, size-1);  // Point A
   }  // end if
 
   // size == 0 is the base case - do nothing
}  // end writeBackward
int main()
{
    string s = "Hello there";
cout << "s has " << s.length() << " characters." << endl;
   string theString = "";

   cout << "Enter a (backward) string: ";
   getline(cin, theString);

   cout << reverse(theString) << endl;

   return 0;
}  // end main

string reverse(string& s, int size)
{
   
   // Implement me!!!
}  // end reverse

"reverse" < aðal ! {
aðal -> stef (;)
    stofn
        \skrifastreng \reverse "Hax my anus"
    stofnlok

reverse -> stef(;s)
    ;; Reverses a string in-place.
    staðvær t, i, l := \lengd s, j := l
    stofn
        fyrir (i := 1; i < j; i := \stækka i, j := \minnka j) lykkja
            t := s[i],
            s[i] := s[j],
            s[j] := t
        lykkjulok,
        s
    stofnlok  
}
*
"GRUNNUR"
;

It took me a while to figure out that Fjölnir strings are actually indexed from 1 to n, not 0 to n-1. Further, Fjölnir strings are prefixed with a length byte (presumably the maximum length is 255...), which, if you don't know about the 1 to n indexing, can easily be overwritten with a careless s[0] := 'a' or equivalent. Fjölnir never ceases to surprise me.

>>11,2,4

string reverse(const string& s) {
    return string(s.rbegin(), s.rend());
}