Re: serializing and deserializing enum type

From:

"Jim Langston" <tazmaster@rocketmail.com>

Newsgroups:

comp.lang.c++

Date:

Wed, 15 Aug 2007 00:19:38 -0700

Message-ID:

<gOxwi.54$_Y6.15@newsfe02.lga>

"Jim Langston" <tazmaster@rocketmail.com> wrote in message
news:rdxwi.53$_Y6.24@newsfe02.lga...

<yu_kuo@sina.com> wrote in message
news:1187082154.724455.50100@w3g2000hsg.googlegroups.com...

I got series warning when using write enum type to a ostream using
operator<<, like

in call to `std::basic_ostream<_CharT, _Traits>&
std::basic_ostream<_CharT, _Traits>::operator<<(int) [with _CharT =
char, _Traits = std::char_traits<char>]'
A.cpp:60: warning: passing `NAME_ENUM' chooses `int' over `long int'

Compiler gcc 3.4.3

When deserialize from an istream, I have to first using an int, and
then cast to the enum type. And need check the range on the spot.

I do know I can overload operator<< and >> for enum type, but do that
for every enum type isn't too boring? I'm wondering a way to do it in
one strike, is there?

You can overload operator<< and >> for enum type? I didn't think you
could override << >> for C++'s built in types. I'm going to have to play
with that. Right now I'm doing:

int Race, Sex;
is >> CChar.GM >> /* ... */ Race >> Sex /* ... */ ;
CChar.Race = static_cast< ERaces >( Race );
CChar.Sex = static_cast< ESexes >( Sex );

Overloading operator << and >> for my ERaces and ESexes enums would make
it a lot cleaner.

This seems to work:

enum ERaces
{
    Raceless,
    Human,
    Angel,
    Fiend,
    Demon
};

std::istream& operator>>( std::istream& is, ERaces& Race )
{
    int IntRace;
    is >> IntRace;
    Race = static_cast< ERaces >( IntRace );
    return is;
}

Good enough for me.