VS2019 Manual build, not using cmake.
I tried two versions
1.8.1 1.9.0
auto aRet = torch::cuda::is_available(); // 1.8.1 = false ,1.9.0 = true
auto adRet = torch::cuda::device_count(); // 1.8.1 = 0 ,1.9.0 = 1
torch::Tensor b = torch::randn({ 2, 2 });
b.to(torch::kCUDA);    //All errors

1.9.1 Tips  c10::NotImplementedError
Here are the libraries I included
opencv_world410.lib
c10.lib
c10_cuda.lib
torch.lib
torch_cpu.lib
torch_cuda.lib
torch_cuda_cu.lib
torch_cuda_cpp.lib
pytorch_jni.lib
cudart_static.lib
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