Prevent specifying each integral value as unsigned in array-initializer

Consider the following function which takes a reference to an array of a size N deduced at compile time:

template <size_t N>
void array_consumer(unsigned const (&source)[N]) {
  // ...
}

I want to call it with an array initializer like this:

array_consumer({1u, 2u, 3u, 4u});

This works, but I don't want to specify the u after every value (the actual arrays may be much longer). Is there something I can do to the function signature or at the call site to avoid this?

Note that I need the array to actually be of unsigned type inside array_consumer (and I don't really want to make a copy) so changing the signature to int const (&source)[N]) doesn't work.