"Pavel Vozenilek" <pavel_vozenilek@hotmail.com> writes:
2. Sounds like it should be true if any of the values in a equals none of the values in b.
That sounds right to me.
No, the (2) should be true if any value from 'a' cannot be equaled to some single value from 'b'. This would make it symetrical to (1).
That sounds completely counterintuitive.
Say: a = green, blue, blue b = blue, red
none_of(a) == any_of(b) is false because there is blue (even 2 of them) from 'a' that match something in 'b'
any_of(a) == none_of(b) is false because there are two different cases when blue from 'a' is in 'b'.
No, it should be true, because there is something in a that is equal to nothing in b. any_of(x) == whatever should always be equivalent to x[0] == whatever x[1] == whatever x[2] == whatever Anyway, saying that symmetry requires none_of(a) == any_of(b) to be equivalent to any_of(a) == none_of(b) is about as valid as saying 3*x == 1+y must be equivalent to 1+x == 3*y It makes no sense to me. -- Dave Abrahams Boost Consulting www.boost-consulting.com