Re: [boost] New libraries implementing C++11 features in C++03

Subject: Re: [boost] New libraries implementing C++11 features in C++03
From: Lorenzo Caminiti (lorcaminiti_at_[hidden])
Date: 2011-11-24 15:36:28

On Thu, Nov 24, 2011 at 12:56 PM, Thomas Klimpel
<Thomas.Klimpel_at_[hidden]> wrote:
> Dean Michael Berris wrote:
>> Or better yet, works now:
>>
>> namespace foo {
>>   void non_local_function(int i, bool b, long l, std::string const & s)
>> {
>>     // do what I want here.
>>   }
>>
>>   void f(std::vector<double> const &v) {
>>     int i;
>>     bool b;
>>     long l;
>>     for_each(begin(v), end(v), bind(&non_local_function, i, b, l, _1));
>>   }
>> }
>>
>> See, no voodoo required here.
>
> To be honest, this one really looks nice and convincing. I find it even looks nicer than the C++11 Lambda. And as you wrote in response to Lorenzo:
>
>> But I did show a solution that works in both C++03 and C++11 which is
>> to use bind to do it and a non-local function. Phoenix already enables

As you say this solution, which works on both C++03 and C++11, does
not implement a local function. N2511 indicates one prospective
arguing maintenance and readability benefits when the function can be
declared locally, e.g., just above the for_each in this case. That is
not possible in your example. That's what Boost.Local does instead.
(Note that with your example above you also explicitly specified the
bound types but I'm sure you can workaround that with templates so I'm
not arguing this point as an issue.)

Now, it is really OK if you think that local functions are not needed.
IMO, as a user you should be fully empowered to use or not a library
based on your personal preferences and the needs of your problem
domain. As for the library under review, as I said, the reviewers have
directly spoken to the question of whether local functions are or not
useful:
> - What is your evaluation of the potential usefulness of the library?

HTH,
--Lorenzo