message: Allow constructing rdcfixedarray with a fixed size array
diff: @@ -888,6 +888,11 @@ public:
  return *this;
  }
  rdcfixedarray() = default;
  + rdcfixedarray(const T (&in)[N])
  + {
  + for(size_t i = 0; i < N; i++)
  + elems[i] = in[i];
  + }
  rdcfixedarray(const std::initializer_list<T> &in)
  {
  static_assert(std::is_trivial<T>::value,
  