Re: [boost] [BGL] why not breakup put_get_helper into three structs?

From: David Abrahams (dave_at_[hidden])
Date: 2008-08-07 17:40:08

on Thu Aug 07 2008, Andrew Sutton <asutton-AT-cs.kent.edu> wrote:

>>> You might also consider that the BGL is fairly dated and stagnant,
>>> and in need of some serious TLC. Whether or not property maps
>>> continue to exist in the same form in future renditions of the
>>> library is anybody's guess - I'm leaning towards "no".
>>
>> Hm, and what do you propose as an alternative?  I can't see how we
>> could
>> do without them.
>>
>> I might like some trivial syntactic changes
>>
>>   get(m, k) ==> m(k)
>>   put(m, k, v) ==> m(k,v)
>>
>> but that's about it.
>
>
> Basically, yeah. With the addition of lambda expressions, the put/get
> functions could basically disappear, and the act of building property
> maps becomes the art of writing lambda functions. At least, that's
> the theory. The concepts don't really change either. There can still
> a read, write, and lvalue concepts. They just appear as:
>
> m(k) 	// read
> m(k, x) 	// write
> m(k) = x 	// lvalue

Personally I don't think there should be an lvalue concept.  Is there
really an algorithm that requires it?

> Or something like that. I have part of an implementation of new
> property maps in my SoC directory (sandbox/SOC/2008/graphs).

OK, but that's certainly not "property maps continue to exist in the
same form...."  Ugh, now that I copied your words out, I realize you
said "the same" and not "some," which changes everything.  Sorry for the
noise.

It pays to read carefully.

-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com