class FFI::VariadicInvoker

def attach(mod, mname)
  invoker = self
  params = "*args"
  call = "call"
  mod.module_eval <<-code
  @@#{mname} = invoker
  def self.#{mname}(#{params})
    @@#{mname}.#{call}(#{params})
  end
  def #{mname}(#{params})
    @@#{mname}.#{call}(#{params})
  end
  code
  invoker
end

def call(*args, &block)
  param_types = Array.new(@fixed)
  param_values = Array.new
  @fixed.each_with_index do |t, i|
    param_values << args[i]
  end
  i = @fixed.length
  while i < args.length
    param_types << FFI.find_type(args[i], @type_map)
    param_values << args[i + 1]
    i += 2
  end
  invoke(param_types, param_values, &block)
end

def init(arg_types, type_map)
  @fixed = Array.new
  @type_map = type_map
  arg_types.each_with_index do |type, i|
    @fixed << type unless type == Type::VARARGS
  end
end