pytorch--BoolTensor进行逻辑运算操作

since pytorch 1.2, there is a dtype torch.bool and associated BoolTensor. The bitwise operators aka numpy (and &, or |, xor ^ and not ~) all work on these as logical operations.

BoolTensor在pytorch1.2后引入，针对BoolTensor才有了如下逻辑运算（dtype为bool型）

• 与操作：a & b
• 或操作：a | b
• 异或操作：a ^ b
• 取反操作：~a

参考自Implementing element-wise logical and tensor operation