ifstream breaks after reading a file 3 times - c++

Question

Im picking up values from a .txt file using ifstream. i am also using windows library to read all files in a folder, that is loop over until the end of folder is reached. In this loop I am reading values from a txt file and adding it to a matrix using push_back.
Here is the section of code under question:
Mat trainme(0, dictionarySize, CV_32FC1);
Mat labels(0, 1, CV_32FC1); //1d matrix with 32fc1 is requirement of normalbayesclassifier class
hTrain = FindFirstFile(full_path, &TrainData);
if (hTrain != INVALID_HANDLE_VALUE)
{
ifstream file("c:\\222\\labels.txt");
string line;
do {
strcpy(loc,DirSpec);
Mat img = imread(strcat(loc,TrainData.cFileName), 0);
cout<<"Processing file: "<<TrainData.cFileName<<endl;
if (!img.data){
cout << "Image data not loaded properly: " <<TrainData.cFileName<< endl;
cin.get();
}
vector<KeyPoint> keypoints;
features->detect(img, keypoints);
if(keypoints.empty()) cout<<"Cannot find keypoints in image: "<<TrainData.cFileName<<endl;
Mat bowDescriptor;
bowDE.compute(img, keypoints, bowDescriptor);
trainme.push_back(bowDescriptor);
getline(file, line);
labels.push_back(line);
strcpy(loc,"");
} while( FindNextFile(hTrain,&TrainData));
}
The problem arises at the line labels.push_back(line); after 3 loops. I mean the file is read 3 times and after that the error: Access violation writing location. And points to this line in memcpy.asm:
mov [edi],al ;U - put byte in destination
I cannot figure out why it fails. I thought it may be a problem transferring string format so I used float value = atof(line) but that gave an error that it cannot convert from string format and it can only take the old c style string.
Here is what is contained in the labels.txt
1
2
2
2
1
2
2
2
Thank you for looking.
Update: I tried moving the file reading out of the main loop and used while(file.good()) But I still get the same error at the same spot. I have no idea why.
string line;
ifstream file("c:\\222\\labels.txt");
if (file.is_open())
{
while (file.good() )
{
getline (file,line);
labels.push_back(line);
}
file.close();
}

Answer 1

Alrighty, I managed to get it solved... =/
The problem was here: labels.push_back(line);
I think adding std::string to Mat using push_back is not possible.
I solved it by converting the string to float using atof.
getline (file,line);
float label = atof(line.c_str());
labels.push_back(label);