Please read tips for efficient and successful posting and posting code ROOT Version: Not Provided Platform: Not Provided Compiler: Not Provided The following snippets are adapted from the Manual . I created an empty file.root and ran the following. void ownership() { TFile myFile("file.root…

but is that because h1 “owns itself” Close enough :). It is because h1 is created on the stack and thus is destructed at the end of the function. My guess is that h1 automatically got owned by myFile, so at the end of the scope h1 was deleted Correct. To solve your issue, take ownership of …

Thanks! I guess I don’t really know what is meant by ownership here. Does it make sense to talk about ownership when it comes to something created on the stack? As in, if h is created on the stack, can it be owned by anyone?

In this case you can think of the local ‘stack’ or ‘scope’ as owning the object.

Following page 10 of some slides online, I tested the following, which seg faults void ownership() { TFile myFile("file.root", "RECREATE"); std::unique_ptr<TH1F> h1(new TH1F("h3","Histogram from a Gaussian",100,-3,3)); myFile.Close(); h1->FillRandom("gaus",10000); h1->Draw(); } and this…

[image] unmovingcastle: Am I correct to assume that even with unique_ptrs ROOT will take ownership of histograms, but not if the histogram is on the stack? Correct.

ROOT Manual - Basics: Object Ownership Question

Newbie

pcanal October 23, 2025, 10:46pm 6

Correct.