Recursively defined matcher function

[Per Nordlöw]

How can I define a function type `Matcher` that takes an array of 
`Matcher`s and returns an instance of a `struct Match` defined as

struct Match
{
@safe pure nothrow @nogc:
     static Match zero()
     {
         return typeof(return)(0);
     }
     static Match none()
     {
         return typeof(return)(_length.max);
     }
     /// Match length in number of UTF-8 chars or 0 if empty.
     @property uint length()
     {
         return _length;
     }
     bool opCast(U : bool)() const
     {
         return _length != _length.max;
     }
     this(size_t length)
     {
         assert(length <= _length.max);
         this._length = cast(typeof(_length))length;
     }
     const uint _length;                // length == uint.max is 
no match
}

I've tried

     alias Matcher = Match function(Matcher[] matchers...);

but it errors as

     recursive alias declaration