Re: [boost] Re: Re: IOStreams formal review start

From: Rob Stewart (stewart_at_[hidden])
Date: 2004-09-10 15:50:38

From: "Jonathan Turkanis" <technews_at_[hidden]>
> "Rob Stewart" <stewart_at_[hidden]> wrote in message
> news:200409101906.i8AJ6M921012_at_lawrencewelk.systems.susq.com...
> > From: "Jonathan Turkanis" <technews_at_[hidden]>
> 
> > >     enum {
> > >         f_open             = 1,
> > >         f_input_closed     = f_open << 1,
> > >         f_output_closed    = f_input_closed << 1,
> > >         f_output_buffered  = f_output_closed << 1
> > >     };
> >
> > This is a pain to read and maintain.  You should write them like
> > this:
> >
> > enum
> > {
> >    f_open            = 1<<0,
> >    f_input_closed    = 1<<1,
> >    f_output_closed   = 1<<2,
> >    f_output_buffered = 1<<3
> > };
> >
> I stole this idiom from John Maddock: http://tinyurl.com/4no5s. It's supposed to
> make insertion in the middle easier. I think it's the vector vs. list tradeoff.

It fails to make insertion in the middle easy, at least
comparatively.  Start with:

   Yours/John's            Mine
enum
{
   name_a = 1,             1<<0,
   name_b = name_a << 1,   1<<1,
   name_c = name_b << 1    1<<2
};

Now add name_x after name_b:

enum
{
   name_a = 1,             1<<0,
   name_b = name_a << 1,   1<<1,
   name_x = name_b << 1,   1<<2,
   name_c = name_x << 1    1<<3
};

Your version requires a more extensive change due to the use of
the enumerator name and makes it harder to determine if the new
order is, in fact, sequential.

-- 
Rob Stewart                           stewart_at_[hidden]
Software Engineer                     http://www.sig.com
Susquehanna International Group, LLP  using std::disclaimer;