Transform help

I am doing lab for homework, I have the code seemingly correct except when I compile I get an error:

hangman.cpp no matching function for call to `transform(__gnu_cxx::__normal_iterator<char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, __gnu_cxx::__normal_iterator<char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, __gnu_cxx::__normal_iterator<char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, <unknown type>)'

Headers etc..

Code:

---

#include <iostream>
#include <algorithm>
#include <string>

using namespace std;
using std::transform;
int main ()
{
    // declare variables
    string origWord  = "";
    string letter    = "";
    char dashReplaced = 'F';
    char gameOver    = 'F';
    int numIncorrect = 0;
    string guessWord = "-----";

---

transform itself. I can post more parts if this does not show enough.

Code:

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transform(origWord.begin(), origWord.end(), origWord.begin(), toupper);

---

Not sure why it is doing this, this is the only error (there are 2 transforms and both get same error)

Does it work with the global ::toupper?

using std::toupper? No same error.

Code:

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transform(origWord.begin(), origWord.end(), origWord.begin(), tolower);

---

I tried this way too, to double check. Same error.

It doesn't like toupper, because it's ambiguous. Try:

Code:

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transform(origWord.begin(), origWord.end(), origWord.begin(), (int(*)(int)) toupper) );

---

Source: http://www.devx.com/getHelpOn/Article/9702/1954

Crap that works perfect. Wonder why the book was wrong? Or could it be that I left something else out?
Thanks for your help.

Maybe:

Code:

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#include <cctype>

---

... might help to include the header that actually contains the prototype for that function.

Nope, I changed it back and added the cctype header and got the same error. I thought it (toupper) was covered under <iostream>? Tranform is supposed to be <algorithm>