Bill Baxter wrote: > Note that D already has things like !>. But quoth the spec: > "For floating point comparison operators, (a !op b) is *NOT* the same > as !(a op b)." > [emphasis added]
I had to check the spec for the difference. 'a !< b' and '!(a < b)' /are/ equivalent in the sense that '(a !< b) == !(a < b)' for any values of 'a' and 'b'. The vast majority of the time, the expressions 'a !< b' and '!(a < b)' /are/ interchangeable. The difference is that '!(a < b)' sets a global exception state if either operand is NaN, while 'a !< b' does not. This is, in my opinion, a significant design error in the language. The difference between '!(a < b)' and 'a !< b' is not obvious. There is nothing about the operator '<' that suggests that it should set a global exception state, and there is nothing about '!<' that suggests that it should /not/ set a global exception state. (Is global state for error reporting ever a good idea in a high-level language?) It also adds awkward expressions to the language, not just in the form '!(a < b)', but in the form '!(a !< b)'. -- Rainer Deyke - rain...@eldwood.com