[C++-sig] Bitflags

[David Abrahams]

"M. Evans" <datafeed at SoftHome.net> writes:

>> No... what I meant by flags was:
>> 
>> enum Fu { x = 1, y = 2, z = 4 };
>> 
>> Fu combined = x | y | z;
>
> Commonly called "bitflags," and in my book, deprecated -- though I have
> used them extensively.  Their main advantage is syntactical.  I don't
> know the context here precisely, but bitflags make combinations of
> "rules" or "options" easy to write.
>
> The problem is the limitation thus imposed on the number of possible
> options (e..g 16 or 32).

The point is that the library is designed to make it easy to use
common C++ idioms from Python, not to pass judgement on which idioms
are good or bad.

If it were impossible to construct unnamed values of a wrapped enum,
it would interfere with common use cases.

-- 
                       David Abrahams
   dave at boost-consulting.com * http://www.boost-consulting.com
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