无效的类型std::istream*'和'char'到二进制'运算符>>'

I have a rudimentary function:

我有一个基本的功能:

TokenType getToken(istream *in, string& recognized){
    char token;
    in >> token;
    if (token=='#'){
        in.ignore('\n');
        in >> token;
    }
    return T_UNKNOWN;
}
T