c++ - Qt reading file and mapping to QVector very slow (crashes) -

so trying read file , map 2 dimensional qvector. here code far

void datamodel::parsefilebylines() { qvector<qvector<qstring> > dataset; lasterror = ""; qregexp reg(filedelimiter); qfile infile(inputfile); if (infile.open(qiodevice::readonly)){     qtextstream fread(&infile);     long totalsize = infile.size();     qstring line;     while(!fread.atend()){         line = fread.readline();           dataset.append(line.split(reg,qstring::keepemptyparts).tovector());    } }else{    lasterror = "could not open "+inputfile+" reading"; } } 

my issue when dealing 1000,000 lines or more program crashes message saying "this application has requested runtime terminate in unusual way". there more efficient way can achieve goal ? if how ?

the input file may in format so

id,name,age,gender...etc

1,sam,12

...

...

1000000

i appreciate or advice

i have tested (qlist) version here on computer , runs faster qvector version , believe not crash.

void parsefilebylines(qstring inputfile) {     qlist<qlist<qstring> > dataset;     qstring lasterror = "";     qfile infile(inputfile);     if (infile.open(qiodevice::readonly)){         qtextstream fread(&infile);         long totalsize = infile.size();         qstring line;         while(!fread.atend()){             line = fread.readline();             qlist<qstring> record = line.split('\t',qstring::keepemptyparts);             dataset.append(record);         }     }else{         lasterror = "could not open "+inputfile+" reading";     } }