Subj : Re: std streams and enum?
To   : alt.comp.lang.learn.c-c++,borland.public.cpp.borlandcpp
From : Ulrich Eckhardt <doomster@knuut.de>
Date : Mon Dec 22 2003 12:42 am

Maya wrote:
> enum account_t {Zero, One, Two};
>     std::istream&
>        jme::operator>>(std::istream& is, jme::Account& obj){
>            is >> obj.type;  // <<======== Here is the problem ****
>            return is;
>        }

> account.H: In function `std::istream& jme::operator>>(std::istream&,
>     jme::Account&)':
> account.H:91: no match for `std::basic_istream<char, 
> std::char_traits<char> >&
>     >> jme::account_t&' operator <<<<<<<====== This is the problem *****
> ...: candidates are:

Well, how should IOStreams know about your enumeration and how it is
supposed to be written to a stream? One simple solution is to overload the
operator for it, another is to just use a temporary int and a
static_cast<>.

One more note, you can nest enumerations inside classes/structs:
class Account
{
  enum Type
  { one, two, three };
};
The fully qualified type is then Account::Type (just like with namespaces).

Uli

-- 
Questions ?
see  C++-FAQ Lite: http://parashift.com/c++-faq-lite/  first !

.