private ILocalNArray CreateLocalLike <S, T>(NArray <T> array)
        {
            if (_builder.VectorLength == -1)
            {
                _builder.VectorLength = array.Length;
            }
            if (array.Length != _builder.VectorLength)
            {
                throw new ArgumentException("length mismatch", "array");
            }

            return(_builder.CreateLocal <T>());
        }