A lot of totally deranged contortions in C++, if you are lucky to find someone sharing the "secret" committee discussions, end up being caused by interaction of ODR, ADL, decay and other equally disease-sounding features. Like, I'd like to know how many people that can use C++ comfortably could write implementation of std::move and std::forward without looking. Or even tell which is which. Actually, let's try:

    template<typename T> T&& function_1(remove_reference_t<T> &x) {
        return static_cast<T &&>(x);
    }
    template<typename T> remove_reference_t<T> && function_2(T &&x) {
        return static_cast<remove_reference_t<T &&> >(x);
    }

Which one is move and which is forward?

Now, since all this jenga must remain functional, the only option they have to try and fix stuff that is a complete misfeature (like "this" being a pointer) is either requiring you to write make_this_code_not_stupid keywords everywhere ("explicit", "override", ...), or introduce magic rewriting rules (closures, range for, ...)

some fixes go much lower, "decltype(auto)" being a pinnacle of language design that will unlikely be surpassed.