When does the TObject pointed to by TFile::Get(name) go out of scope?

Newbie
4

Thanks for the replies! They were very helpful for understanding ownership a little better.

If I understand correctly, will the following work correctly without giving me a dangling pointer?

TH1D* get_histogram() {
    TFile filename ("input_file.root");
    TH1D* histogram_in_function = filename.Get<TH1D>("histogram_name");
    histogram_in_function->SetDirectory(nullptr); // I added this line
 
    return histogram_in_function;
}

int main() {
    TH1D* histogram_in_main = get_histogram();  // will this be a dangling pointer??
 
    delete histogram_in_main;  
}

Or better yet, with smart pointers:

std::unique_ptr<TH1D> get_histogram() {
    TFile filename ("input_file.root");
    std::unique_ptr<TH1D> histogram_in_function( filename.Get<TH1D>("histogram_name") );
    histogram_in_function->SetDirectory(nullptr); // I added this line
 
    return histogram_in_function;
}

int main() {
    std::unique_ptr<TH1D> histogram_in_main = get_histogram();  // will this be a dangling pointer??
}