torch.cat raises error when given out tensor

[apaszke]

Reported by @chenyuntc

---

seems to cause error

import torch as t
a=t.Tensor(2,4)
b=t.Tensor(2,4)
c=t.Tensor(2,8)
t.cat(a,b,out=c)

TypeError                                 Traceback (most recent call last)
<ipython-input-1-ce3d61609aec> in <module>()
      3 b=t.Tensor(2,4)
      4 c=t.Tensor(2,8)
----> 5 t.cat(a,b,out=c)

TypeError: cat received an invalid combination of arguments - got (torch.FloatTensor, torch.FloatTensor, out=torch.FloatTensor), but expected one of:
 * (sequence[torch.FloatTensor] seq)
 * (sequence[torch.FloatTensor] seq, int dim)

also see https://discuss.pytorch.org/t/cat-got-an-unexpected-keyword-argument-out/2151

[colesbury]

The call to cat is wrong.

t.cat([a,b], out=c) not t.cat(a,b,out=c)