I noticed a strange behavior when choosing the Microsoft Visual C++ 17 language. Structured binding is handled incorrectly.
Let's be concrete. I tried to solve that problem: https://codeforces.net/contest/1843/problem/E and noticed that exactly the same code leads to different decisions on different compilers. Namely, it was accepted when choosing G++17 (as well as G++20, Clang++20): https://codeforces.net/contest/1843/submission/210710990 and when choosing VC++17 it gave wrong answer on test 1: https://codeforces.net/contest/1843/submission/210711015 A small investigation showed that the problem was in the lines when I filled a vector of pairs using structured binding:
vector<pair<int, int>> segments(m);
for (auto& [l, r] : segments)
cin >> l >> r;
As one can see from this submission: https://codeforces.net/contest/1843/submission/210711251 elements of the vector are not filled with input values for some reason, and remain the default zeroes.
I want to add that I couldn't reproduce the bug on my version of MSVC++ (Version 17.5.3). The problem was only with the compiler on the server. Is it some known bug of the MSVC++ compiler used on Codeforces? If it is, are there some more that are commonly known?