Must default function parameters be constant in C++?

Question

void some_func(int param = get_default_param_value());

Answer 1

David Rodríguez - dribeas answear is great, but doesn't provide a solution.
It may look like there is no solution.

Solution is quite simple: repalce default parameter with function/method overload.

void some_func(int param);
void some_func() {
    some_func(get_default_param_value());
}