How to convert a string iterator to a char*

[AndreasL]

Hi!

I have a string passed to a methos via a string&. I would like to convert this to an unsigned long.

How do I convert the string iterator to a char*?

with all the error checking code removed, it's basically this:

MyFunction(string &s)
{
    string::iterator it = s.begin();
    // Sometimes the string is iterated a few characters here
    DWORD value = strtoul(it, NULL, 16);
    // Post processing data
}
 

When I try to execute this code I get this error message.

error: cannot convert '__gnu_cxx::__n ormal_iterator< char*, std::basic_stri ng<char, std::char_trait s<char>, std::allocator< char> > >' to 'const char*' for argument '1' to 'long unsigned int strtoul(const char*, char**, int)'|

[Oralloy]

try

MyFunction(string &s) 
{ 
    string::iterator it = s.begin(); 
    // Sometimes the string is iterated a few characters here 
    DWORD value = strtoul(s.c_str(), NULL, 16); 
    // Post processing data 
} 

[Oralloy]

Just as an aside, why aren't you wrapping a stream around the string and just extracting values that way?