std::map iterator

[Christopher]

I am having problems iterating through the sequence of objects stored in my
std::map I want to call a function from the "value" object in the map. Here
is my snippet:

typedef std::map<SOCKET , Player> PLAYERMAP_SOCKE T;

.....
BOOL Player::Send(st d::string data)
......
// Send the text to all clients
PLAYERMAP_SOCKE T::iterator it;
for(it = players_by_sock et.begin(); it!= players_by_sock et.end(); ++it)
*it.Send(std::s tring(textbuff) );
.......
error C2039: 'Send' : is not a member of 'pair<unsigned int const ,class
Player>'

how do I call the function from the "pair"?

Thanx,
Christopher

[Rob Williscroft]

Re: std::map iterator

Christopher wrote in news:rUo2b.799$ f76.26049@twist er.austin.rr.co m:
[color=blue]
> I am having problems iterating through the sequence of objects stored
> in my std::map I want to call a function from the "value" object in
> the map. Here is my snippet:
>
> typedef std::map<SOCKET , Player> PLAYERMAP_SOCKE T;
>
> ....
> BOOL Player::Send(st d::string data)
> .....
> // Send the text to all clients
> PLAYERMAP_SOCKE T::iterator it;
> for(it = players_by_sock et.begin(); it!= players_by_sock et.end();
> ++it)
> *it.Send(std::s tring(textbuff) );[/color]

it->second.Send( std::string(tex tbuff) );

[color=blue]
> ......
> error C2039: 'Send' : is not a member of 'pair<unsigned int const
> ,class
>Player>'
>[/color]

Are you sure. In the above you're calling Send( ... ) on a
std::map< SOCKET, Player >::iterator:

(*it).Send(std: :string(textbuf f));

or

it->Send(std::stri ng(textbuff));

should produce that error.
[color=blue]
> how do I call the function from the "pair"?
>[/color]

The iterator for your map (conceptualy) points to a
std::pair< SOCKET const, Player > a pair has two elements 'first'
and 'second'. In this case 'first' is your map's key (constant)
and 'second' is your map's value (non-constant).


HTH

Rob.
--

http://www.victim-prime.dsl.pipex.com/

[Christopher]

Re: std::map iterator


"Agent Mulder" <mbmulder_remov e_this_@home.nl > wrote in message
news:bid8ep$dfr $1@news2.tilbu1 .nb.home.nl...[color=blue]
> Ch> I am having problems iterating through the
> Ch> sequence of objects stored in my std::map
> Ch> I want to call a function from the "value"
> Ch> object in the map. Here is my snippet:
> [SNIP]...
>
> #include<map>
> class SOCKET{public:S end(std::string ){}};//which one is sending?
> class Player{public:S end(std::string ){}};//which one is sending?
> int main(int,char** )
> {
> std::map<SOCKET ,Player>players _by_socket;
> for
> (
> std::map<SOCKET ,Player>::itera tor it=players_by_s ocket.begin();
> it!=players_by_ socket.end();
> ++it
> )
> {
> it->first.Send(std ::string());
> it->second.Send(st d::string());
> }
> return 0;
> }
>
> -X[/color]

I think I might have confused some people with my code. SOCKET is not a
class, it's just an integer defined in a 3rd party lib. The Send() function
is a member of the Player class. The intention of making the map is that
when data comes in the program is only provided with the SOCKET, so I use
the map to look up the associated player connected to that socket. So I used
SOCKET as the key and Player as the value. Of course in this case I want to
send to all players so I am just iterating through the enitire list. At any
rate the replies I got provided the needed information: it->second.Send( )
and everything is working with the desired effect now.
Thanx for the helps guys,
Christopher

[Kevin Goodsell]

Re: std::map iterator

Christopher wrote:
[color=blue]
> I am having problems iterating through the sequence of objects stored in my
> std::map I want to call a function from the "value" object in the map. Here
> is my snippet:
>
> typedef std::map<SOCKET , Player> PLAYERMAP_SOCKE T;
>
> ....
> BOOL Player::Send(st d::string data)[/color]

Why are you using BOOL when the language provides the bool type? Is it
an attempt to obfuscate the code or increase the probability of bugs?
[color=blue]
> .....
> // Send the text to all clients
> PLAYERMAP_SOCKE T::iterator it;
> for(it = players_by_sock et.begin(); it!= players_by_sock et.end(); ++it)
> *it.Send(std::s tring(textbuff) );[/color]

This would be wrong even if 'it' pointed to an object that had a member
called 'Send' (which it obviously doesn't). What you have is equivalent to:

*(it.Send(std:: string(textbuff )));

See the problem?

-Kevin
--
My email address is valid, but changes periodically.
To contact me please use the address from a recent posting.

[Christopher]

Re: std::map iterator


"Kevin Goodsell" <usenet1.spamfr ee.fusion@never box.com> wrote in message
news:3f4a93ba@s hknews01...
<snip>[color=blue]
> Why are you using BOOL when the language provides the bool type? Is it
> an attempt to obfuscate the code or increase the probability of bugs?[/color]

You'll have to ask Microsoft that one. If it was up to me I'd be happy with
the types already provided to me.
,
Christopher

[Ron Natalie]

Re: std::map iterator


"P.J. Plauger" <pjp@dinkumware .com> wrote in message news:3f4b6a51$0 $19407$afc38c87 @...
[color=blue]
> Some of us had to write C++ code that used Boolean variables *before*
> type bool was added to the draft C++ Standard. So the answer is doubtless
> `none of the above'. Unless you choose to be aggressively uncharitable.[/color]

Some of us had to program C before structs could be assigned or even before
the member names were scoped to struct. Old habits die hard.