STL

[Roland groenvynck]

I try to use STL to contruct two sets and make the unions of it , but
my program keeps running in a loop when the union is tried :

typedef set<int> TVSet;
void CPSetDlg::OnBut ton1()
{
TVSet V1, V2, V3;
V1.insert (1);
V1.insert (2);

V2.insert (1);
V2.insert (3);



set_union(V1.be gin(),
V1.end() ,
V2.begin(),
V2.end(),
V3.begin()
);
}

Could someone help me?? thank you

[Rob Williscroft]

Re: STL

Roland groenvynck wrote in
news:a952b245.0 404130232.678b2 f7f@posting.goo gle.com in comp.lang.c++:
[color=blue]
> I try to use STL to contruct two sets and make the unions of it , but
> my program keeps running in a loop when the union is tried :
>
> typedef set<int> TVSet;
> void CPSetDlg::OnBut ton1()
> {
> TVSet V1, V2, V3;
> V1.insert (1);
> V1.insert (2);
>
> V2.insert (1);
> V2.insert (3);
>
>
>
> set_union(V1.be gin(),
> V1.end() ,
> V2.begin(),
> V2.end(),
> V3.begin()
> );
> }
>
> Could someone help me?? thank you
>[/color]

#include <iostream>
#include <ostream>
#include <set>
#include <algorithm>
#include <iterator>

int main()
{
using namespace std;

set< int > V1, V2, V3;
V1.insert (1);
V1.insert (2);

copy( V1.begin(), V1.end(), ostream_iterato r< int >( cout, ", " ) );
cout << '\n';

V2.insert (1);
V2.insert (3);

copy( V2.begin(), V2.end(), ostream_iterato r< int >( cout, ", " ) );
cout << '\n';

set_union(
V1.begin(), V1.end(),
V2.begin(), V2.end(),
ostream_iterato r< int >( cout, ", " )
);
cout << '\n';

set_union(
V1.begin(), V1.end(),
V2.begin(), V2.end(),
inserter( V3, V3.end() )
);
cout << '\n';

copy( V3.begin(), V3.end(), ostream_iterato r< int >( cout, ", " ) );
cout << '\n';
}

std::set_union( )'s 5th paramiter needs to be an output iterator,
two examples above.

Rob.
--

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

[red floyd]

Re: STL

SNT_Roland@hotm ail.com (Roland groenvynck) wrote in message news:<a952b245. 0404130232.678b 2f7f@posting.go ogle.com>...[color=blue]
> I try to use STL to contruct two sets and make the unions of it , but
> my program keeps running in a loop when the union is tried :
>
> typedef set<int> TVSet;
> void CPSetDlg::OnBut ton1()
> {
> TVSet V1, V2, V3;
> V1.insert (1);
> V1.insert (2);
>
> V2.insert (1);
> V2.insert (3);
>
>
>
> set_union(V1.be gin(),
> V1.end() ,
> V2.begin(),
> V2.end(),
> V3.begin()[/color]
^^^ -- wrong. Try this instead
std::back_inser ter(V3.begin())[color=blue]
> );
> }
>
> Could someone help me?? thank you[/color]

[red floyd]

Re: STL

redfloyd11@yaho o.com (red floyd) wrote in message news:<968b76.04 04130942.24e6db c4@posting.goog le.com>...[color=blue]
> [proposed set_union problem redacted][/color]

DISCLAIMER: I don't have my copy of the library reference here. I
don't remember if std::set has a back_inserter.

[Kevin Goodsell]

Re: STL

red floyd wrote:
[color=blue]
> redfloyd11@yaho o.com (red floyd) wrote in message news:<968b76.04 04130942.24e6db c4@posting.goog le.com>...
>[color=green]
>>[proposed set_union problem redacted][/color]
>
>
> DISCLAIMER: I don't have my copy of the library reference here. I
> don't remember if std::set has a back_inserter.[/color]

No time to check right now, but it probably doesn't have a push_back()
(why would it?). You probably want std::inserter for std::set.

-Kevin
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