Possible bug in `const_assert_ne!`

[konsumlamm]

const_assert_ne! supports 2 or more arguments. In the latter case, only the first argument is compared to every other argument, meaning that the arguments are not checked for pairwise inequality. For example, the following compiles:

const_assert_ne!(1, 2, 2);

The documentation suggests that all the arguments should be not equal to each other. If that's not the intended behaviour (and this is not a bug), the documentation should be updated to reflect that.