Looking for chars in string.

[ninja9578]

You are looking for the index where the string changes from one char to another?

std::string mystring = "ggaagaaag";
size_t index = 0;
char last = '\0';
for(std::string::iterator i = mystring.begin(); i < mystring.end(); ++i, ++index){
    if (*i != last) std::cout << index;
    last = *i;
}
std::cout << index;

Is that what you are looking for?