//test string
    std::string str = "a9382a_ao-EATSHITANDDIE_-_--__-";
    //go through each character in the string
    for(int i = 0; i < str.length(); i++)
    {
        char c = str[i];
        //if the character doesn't equal '_' or '-'
        if(!(c == '_' || c == '-'))
        {
            //check for numbers
            if(c >= '0' && c <= '9')
                continue;
            //check for upper-case letters
            if(c >= 'A' && c <= 'Z')
                continue;
            //check for lower-case
            if(c >= 'a' && c <= 'z')
                continue;
            //if it gets here, it is neither an alpha character or a number character,
            //and it isn't one of the two exempt characters, so we replace it with a space
            str[i] = ' ';
        }
    }