c++ - unhandled exception Access violation writing location in Visual Studio -

is there way in visual studio 2005 find out pointer or variable causing access violation? tried run in debug mode , break when happens. looking @ call stacks, happens in end of function (see below). using try/catch able find out pointer is?

edit: posting code:

there qt line edit , checkbox in application. toggling checkbox switch data format in line edit. 3'b111 <==> 3'h7. below callback function connected checkbox statechanged signal. exception happens in end of function, when destructing local variables.

// switch hex/binary format. 15'h0000 <==> 15'b000000000000000 void switchdataformat(int checkstate) {     qlineedit* writeregle = this->getwritereglineedit();     string oldtext = writeregle->text().tostdstring();     string newtext = "";     int maxlength;     string reglengthtext = oldtext.substr(0, oldtext.find('\''));     string regvaluetext = oldtext.substr(oldtext.find('\'')+2);     int reglength = this->getreglength();      if (checkstate == qt::unchecked) {         // switch binary format         maxlength = reglengthtext.size() + 2 + reglength;         string binarytext;         (int = 0; < regvaluetext.size(); ++i) {             binarytext += hextobinary(regvaluetext[i]);         }         newtext = reglengthtext + "'b" + binarytext.substr(binarytext.size()-reglength);  // trimming leading zeros fit reglength     }     else {         // switch hex format         maxlength = reglengthtext.size() + 2 + reglength/4 + 1;         newtext = reglengthtext + "'h";         // 0 filling 4*n bits         if (reglength%4 != 0) regvaluetext = string(reglength%4,'0') + regvaluetext;         (int = 0; < regvaluetext.size(); i+=4) {             newtext += binarytohex(regvaluetext.substr(i,4));         }     }      writeregle->setmaxlength(maxlength);     writeregle->settext(qstring::fromutf8(newtext.c_str())); }