Variable not Printing to Cout

[LeafyCircuits]

Hi, LeafyCircuits here.
Somewhere on these forums was a person trying to make a Caesar Encryption program, but was having trouble as to achieving that. Well, I decided to try making one myself, and now I've run into problems :)

For those who haven't studied cryptography, a Caesar Cipher is one of the most basic ciphers. Basically, to create the "key", you shift letters of the alphabet down 3 or 4 letters:
Thus, this shifted 3 letters would turn from this,
ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz
to this,
DEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzABC

Therefor, the letter 'A' becomes 'D', and 'y' becomes 'B'


Anyways, here's the problem. I'm trying to print a string variable to the console using cout, but even though the var is filled with valid, null terminated string, it doesn't print anything. I know it's filled because I've used my debugger and looked at the var in question.
So first, comp specs:
OS: Windows 7 Home Premium 64-bit
IDE: Dev-C++ with C++11; ISO and STL
Compiler: GNU gcc

Here's the code in question:

#include <iostream>
#include <vector>
#include <map>
#include <conio.h>

using namespace std;

void nogetch() {getch();}

ostream& operator << (ostream &out, const vector<char> &vec)
{
         vector<char>::iterator itr=vec.begin();
         for (;itr!=vec.end();itr++)
         {
             cout << *itr;
         }
         return out;
}

map<char, char> createCypherKey(unsigned int adv)
{
             vector<char> key1, key2, *keytemp=new vector<char>;
             char rep;
             for (char i=65;i<91;i++)
             {
                 key1.push_back(i);
             }
             for (char i=97;i<123;i++)
             {
                 key1.push_back(i);
             }
             
             *keytemp=key1;
             
             for (int i=0;i<adv;i++)
             {
                 rep=(*keytemp).at(0);
                 (*keytemp).erase((*keytemp).begin());
                 (*keytemp).push_back(rep);
             }
             
             key2=*keytemp;
             delete keytemp;
             keytemp=0;
             
             map<char, char> key;
             if (key1.size()==key2.size())
             {
                                          for (int i=0;i<key1.size();i++)    //since key1.size()==key2.size(), key2 can substitue key1
                                          {
                                              key[key1.at(i)]=key2.at(i);
                                          }
             }
             
             else
             {
                 system("CLS");
                 cout << "Cypher key creation failed!";
                 nogetch();
                 system("CLS");
                 return key;
             }
             
             return key;
}
             

string encrypt(string chvec, map<char, char> key)
{
       string result;
       vector<char> strbuf;
       char input;
       for (int i=0;i<chvec.length();i++)
       {
           strbuf.push_back(chvec[i]);
       }
       
       for (int i=0;i<strbuf.size();i++)
       {
           input=strbuf.at(i);
           strbuf.at(i)=key[input];
       }
       
       for (int i=0;i<strbuf.size();i++)
       {
           result[i]=strbuf.at(i);
       }
       
       return result;
}

main()
{
      string hold, test;
      map <char, char> keyhold=createCypherKey(3);
      cout << "Enter phrase to be encrypted:\n\n";
      cin >> hold;
      test=encrypt(hold, keyhold);
      cout << test;
      getchar();
      getchar();
}

The functions that do the actual encryption seem to work, but even though I don't think the problem is in there, obviously I'm missing something, so please don't ignore the functions entirely (but I'm pretty sure I've proofread enough times).

As you can see, I call that encrypt function (yes, Cipher is spelt wrong) and place it in the 'test' var, then try to print to the console, but nothing is printed. I looked over my overloaded << operator function, and I deduced that that wasn't the source, for when I removed the code, the same bug happened. Using the debugger, I found out that the var is being filled with what I want in there, so I'm really stumped. But then again, most of the time, I probably forgot some small detail that a common mistake. But hey, we make those from time to time.

Also, if you're wondering why I go through the trouble of placing a string inside of a vector to work with, then put that into a string again in my encrypt function, it's simply so I can return simple types for easy manageability.




I'm quite new to the forums, so constructive criticism is greatly appreciated. Thanks for reading.

[cire]

This code doesn't compile as is, so I'm not sure how you're running it.

When you reach line 86 result is an empty string. You cannot access element i of result because result doesn't have an element i.

#include <cctype>
#include <string>

string encrypt(string chvec, map<char, char> key)
{
    string encrypted = chvec ;

    for ( unsigned i=0; i<encrypted.length(); ++i )
        if ( std::isalpha( encrypted[i] ) )
            encrypted[i] = key[encrypted[i]] ;
  
    return encrypted ;
}