Incredible bug found in __gnu_cxx::rope

Правка en4, от -14, 2021-08-24 22:14:34

Today when I took part in the Round #740 solving problem D. Top-Notch Insertions, my submission failed on test 2 without knowing why. After asserting I found that rope contains unwanted contents and I didn't fix the problem during the contest.

However, when I replace all __gnu_cxx::rope.erase(x) into __gnu_cxx::rope.erase(x, 1), my code works fine (idk if it will pass system test or not; at least, it passes asserting that all elements are rolled back to the initial state).

Then! I found it unbelievable to see the following code from here:

Look at the line 2318, comments: Erase, single character.

However, it calls erase(__p, __p + 1);, who will erase __p + 1 characters starting from the position __p.

I found it incredible since it's part of libstdc++. I don't know if there's a way to report such failure. Could anyone tell me if I can do something with it? (or instead, NEVER USE SUCH FUNCTION IN THE FUTURE)

Thank you!

UPD: I've submitted the bug to gcc.

Fortunately, it's quickly replied by Jonathan Wakely. Unfortunately, just exactly as adamant predicted, Jonathan Wakely wrotes:

We should just delete this class, so I don't have to keep fixing bugs in code that nobody uses or cares about.

Теги bug, __gnu_cxx::rope

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  Rev. Язык Кто Когда Δ Комментарий
en4 Английский -14 2021-08-24 22:14:34 363
en3 Английский -14 2021-08-24 20:53:53 4 Tiny change: 'ld anyone can tell me i' -> 'ld anyone tell me i'
en2 Английский -14 2021-08-24 20:52:13 4 Tiny change: 'ion/126903250) failed o' -> 'ion/126903561) failed o'
en1 Английский -14 2021-08-24 20:51:00 1273 Initial revision (published)