In case of ambiguity for how to use inplace:
a_packed_seq = torch.nn.utils.rnn.pack_sequence([torch.randn(3, 1), torch.randn(2,1), torch.randn(1,1)])
print(a_packed_seq)
dropout_layer = torch.nn.Dropout(p=0.999, inplace=True)
dropout_layer(a_packed_seq[0])
print(a_packed_seq)