[Bug c++/86932] [8 Regression] Empty non-type template parameter pack not considered for SFINAE.

[zennehoy at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86932

--- Comment #1 from zennehoy <zennehoy at gmail dot com> ---
Sorry, I included the problematic void non-type template parameter pack.

The type of std::enable_if_t should be specified as something other than void,
e.g., int:

    #include <type_traits>

    template<class U, typename std::enable_if_t<std::is_const_v<U>, int>...>
    void f() {}

    int main()
    {
        f<int>();
    }