boost::spirit asserts at
 boost::spirit::char\_class::ascii::isalnum()

when passing ascci characters > 127. 

I changed all my private variables from std::string to a 

```
typedef std::basic_string<unsigned char, std::char_traits<unsigned char>, std::allocator<unsigned char> >
 u_string;

```

but still boost uses std:.string internally. What do i have to do ?