Variadic template error: 'In instantiation of' (gcc 9.2)

I'm learning about variadic template on c++17 on the Jason Turner's youtube channel then I copy his example code (shown below). In his video he uses the site godbolt.org with the gcc 7.

#include <utility>

template<typename ... B>
struct Merged : B ... {
       template<typename ... T>
       Merged(T&& ... t) : B(std::forward<T>(t))... {}

    using B::operator()...;
};

template<typename ... T>
Merged(T...) -> Merged<std::decay_t<T>...>;

int main() {
    const auto l1 = []() { return 4; };
    const auto l2 = [](const int i) { return i * 10; };

    Merged merged(l1,
                  l2,
                  [](const double d) { return d * 3.2; });

    return 0;
}

I tried the code in my computer with the gcc 9.2 and I got the follow error:

In instantiation of 'Merged::Merged(T&& ...) (with T = {const main()::&, const main()::&, main()::}; B = {}]':

I tried to use the godbolt site to check it out but it also doesn't compile (with gcc 7.1 and gcc 9.2) and give more errors like:

error: missing template arguments before 'merged'Merged merged(l1,

and

error: expected primary-expression before ')' token [](const double d) { return d * 3.2; });

What this error means and what I need to do do fix it?

Compile line in my computer:

g++ -Wall -fexceptions -O2 -pedantic -Wextra -Wall -std=c++1z -m64  -c /home/thearquitect/Desktop/C++/variadic.cpp -o ~/Desktop/obj/variadic.o
g++ -o ~/Desktop/bin/variadic ~/Desktop/obj/variadic.o -s -m64

godbolt try