redef fun vararg_instance(mpropdef, recv, varargs, elttype)
	do
		# A vararg must be stored into an new array
		# The trick is that the dymaic type of the array may depends on the receiver
		# of the method (ie recv) if the static type is unresolved
		# This is more complex than usual because the unresolved type must not be resolved
		# with the current receiver (ie self).
		# Therefore to isolate the resolution from self, a local StaticFrame is created.
		# One can see this implementation as an inlined method of the receiver whose only
		# job is to allocate the array
		var old_frame = self.frame
		var frame = new StaticFrame(self, mpropdef, mpropdef.mclassdef.bound_mtype, [recv])
		self.frame = frame
		#print "required Array[{elttype}] for recv {recv.inspect}. bound=Array[{self.resolve_for(elttype, recv)}]. selfvar={frame.arguments.first.inspect}"
		var res = self.array_instance(varargs, elttype)
		self.frame = old_frame
		return res
	end

	# FIXME: this is currently buggy since recv is not exact
	redef fun vararg_instance(mpropdef, recv, varargs, elttype)
	do
		elttype = self.resolve_for(elttype, recv)
		return self.array_instance(varargs, elttype)
	end