Why is template parameter pack used in a function argument type as its template argument list not able to be explicit specified

Question

I have the following piece of code:

template 
struct AAA{};

template
void f(AAA *) {}

int          


        

Answer 1

I want to add another solution that invokes the {} notion

template 
struct AAA{};

template
void f(AAA *) {}

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

When the argument is {}, deduction for the parameter is disabled (nondeduced context), so there will be no mismatch and the parameter initialization actually produces a null pointer aswell.