[Interest] Help, please !!!

[Scott Aron Bloom]

The following code works just fine...

#include <QList>
#include <QDebug>
#include <QCoreApplication>

int main( int argc, char ** argv )
{
    QCoreApplication appl( argc, argv );

    QList< QList< int > > theList;

    for( int ii = 0; ii < 10; ++ii )
    {
        QList< int > currList;
        for( int jj = 0; jj < 10; ++jj )
        {
            currList.push_back( ii+jj );
        }
        theList.push_back( currList );
    }

    for( int ii = 0; ii < theList.size(); ++ii )
    {
        qDebug() << theList[ ii ];
    }

    for( int ii = 0; ii < theList.size(); ++ii )
    {
        for( int jj = 0; jj < theList[ ii ].size(); ++jj )
        {
            theList[ ii ][ jj ] -= 10;
        }
    }

    qDebug() << "=====================";
    for( int ii = 0; ii < theList.size(); ++ii )
    {
        qDebug() << theList[ ii ];
    }
}



-----Original Message-----
From: interest-bounces+scott.bloom=onshorecs.com at qt-project.org [mailto:interest-bounces+scott.bloom=onshorecs.com at qt-project.org] On Behalf Of Scott Aron Bloom
Sent: Monday, April 23, 2012 11:29 AM
To: interest at qt-project.org
Subject: Re: [Interest] Help, please !!!

Not true at all..

-----Original Message-----
From: interest-bounces+scott.bloom=onshorecs.com at qt-project.org [mailto:interest-bounces+scott.bloom=onshorecs.com at qt-project.org] On Behalf Of Nikos Chantziaras
Sent: Monday, April 23, 2012 10:44 AM
To: interest at qt-project.org
Subject: Re: [Interest] Help, please !!!

Note that with QList< QList<int> > you can't modify the other lists. 
You'd only be modifying the copies.

On 23/04/12 20:42, Scott Aron Bloom wrote:
> Be careful with
> List->append(&someOtherList );
>
> If someOtherList goes out of scope, you will be pointing to a deleted list.
>
> Since QList uses implicit sharing, the cost of removing the inner pointer isn't that much.
>
> QList<  QList<  int>  >
>
> Is much safer
>
> Scott
>
>
>
> -----Original Message-----
> From: interest-bounces+scott.bloom=onshorecs.com at qt-project.org [mailto:interest-bounces+scott.bloom=onshorecs.com at qt-project.org] On Behalf Of Nikos Chantziaras
> Sent: Monday, April 23, 2012 10:34 AM
> To: interest at qt-project.org
> Subject: Re: [Interest] Help, please !!!
>
> On 23/04/12 20:17, Miguel Milán Isaac wrote:
>> I need to use QList<QList<int>   *>   * list; but I do not know how to
>> initialize it.
>>
>> I want to do something like this:
>> if (! listRemoved->   at (pos) ->   contains (id)) {
>>        //do something
>> }
>
>     QList<  QList<int>*>* list = new QList<  QList<int>*>;
>
>     // Fill it with 10 elements.
>     for (int i = 0; i<  10; ++i) {
>         list->append(new QList<int>);
>         // Or:
>         // list->append(&someOtherList);
>     }
>
> Now every list[i] (or list->at(i)) gives you a QList<int>*.  For example:
>
>     if (!list->at(pos)->contains(id)) {
>         // Do something.
>     }
>
> _______________________________________________
> Interest mailing list
> Interest at qt-project.org
> http://lists.qt-project.org/mailman/listinfo/interest


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Interest at qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest