validateUserName

string validateUserName()(string str,  int  min_length =  3,  int  max_length =  32,  string additional_chars =  "-_",  bool  no_number_start =  true)

Validates a user name string.

User names may only contain ASCII letters and digits or any of the specified additional letters.

Invalid user names will cause an exception with the error description to be thrown.

bool validateUserName(R)(ref  R error_sink,  string str,  int  min_length =  3,  int  max_length =  32,  string additional_chars =  "-_",  bool  no_number_start =  true) if (isOutputRange!(R,  char))

ditto