Dave Abrahams wrote:
I don't think you can evaluate these choices just by looking at the implementations. Before anyone else votes option 1, I'd like to see somebody write the description of the algorithm, including the concept requirements.
Well we can start by copying what the experts wrote for std::find, can't we? For the non-predicate version it just says "Returns: The first iterator i in the range [first,last) for which *i==value holds" (n3242). none_of_equal could be written in the same style. But you seem to want something different than that; I guess that you want to add a requirement on the type of the value, right? If so, why do you want that even though it wasn't deemed necessary for the standard? But in any case, it's not hard to write; just require that T is a type for which *i==value is valid. What am I missing? Regards, Phil.