Non-typename arguments in angle brackets vs in parentheses

// Called with doSomething<5>();
template<unsigned i_>
void doSomething()
{
    std::cout << i_ << '\n';
}

// Called with doSomething(5);
void doSomething(unsigned i_)
{
    std::cout << i_ << '\n';
}

When is the first option preferred? Why is it even available? I understand it's useful for classes where the arguments in angle brackets are tied to the object itself, not a specific constructor, but is it useful for functions?