>The amazing part about examples like that is people read them, check that the compiler really does work on that basis, and then continue writing things in C++ anyway. Wild.

Well, in modern C++ this code would look like this:

    std::array<int, 4> table;
    bool exists_in_table(int v)
    {
        for (auto &elem : table) {
            if (elem == v) return true;
        }
        return false;
    }

Or even simpler:

    std::array<int, 4> table;
    bool exists_in_table(int v)
    {
        return std::ranges::contains(table, v);
    }

There's no shortage of footguns in C++, but nonetheless, modern C++ is safer than C.