Re: [boost] [convert] Now with Boost.Parameter interface.

Subject: Re: [boost] [convert] Now with Boost.Parameter interface.
From: Emre Turkay (emreturkay2_at_[hidden])
Date: 2009-05-06 04:41:33

Hi Vladimir,

I think ability to set persistent behavior would be nice. Something like this;

1. convert::set(locale_ = new_locale)(throw_ = true);
2. int i = convert<int>::from(str1, 0);
3. int j = convert<int>::from(str2, 0);

The line #1 effect lines following it (#2 & #3).

Take care,

     emre

On Mon, May 04, 2009 at 02:12:10PM +1000, Vladimir.Batov_at_[hidden] wrote:
> I've incorporated, uploaded to the Vault and started playing with the 
> Boost.Parameter-based interface that Andrey Semashev was insisting from 
> the set-go. And it is definitely growing on me and I like
> 
>         int i = convert<int>::from(str, 0)(locale_ = new_locale)(throw_ = 
> true);
> 
> instead of the original
> 
>         int i = convert<int>::from(str, 0) >> new_locale >> dothrow;
> 
> I think people generally did not like locales and dothrow behaving like 
> manipulators.
> 
> The more I use the Boost.Parameter-based interface the more I am inclined 
> to push it further and apply it to manipulators as well. I.e. 
> 
>         int i = convert<int>::from(str)(radix_ = 16);
> 
> instead of the original direct handling of std manipulators.
> 
>         int i = convert<int>::from(str) >> std::hex;
> 
> Something, again, Andrey was advocating from the start. Now it feels like 
> allowing io-stream manipulators exposes too much implementation detail and 
> raises some unwarranted expectations.
> 
> That raises a few questions that I am hoping people could help me with:
> 
> 1. Both interfaces (for locale and dothrow) are currently supported:
> 
> #1        int i = convert<int>::from(str, 0)(locale_ = new_locale)(throw_ 
> = true);
> #2        int i = convert<int>::from(str, 0) >> new_locale >> dothrow;
> 
> Should I remove #1?
> 
> 2. Both interfaces 
> 
> #1        int i = convert<int>::from(str, 0) >> std::hex;
> #2        int i = convert<int>::from(str, 0)(radix_ = 16);
> 
> are currently supported. Should I move away from direct manipulator 
> support and remove #1?
> 
> 3. I only managed to figure out how to supply only one Boost.Parameter at 
> a time like
> 
>         int i = convert<int>::from(str, 0)(locale_ = new_locale)(throw_ = 
> true);
> 
> I understand how to achieve
> 
>         int i = convert<int>::from(str, 0)((locale_ = new_locale, throw_ = 
> true));
> 
> (with double quotes) but do not want to go there as it looks somewhat 
> unorthodox. I cannot figure out how to achieve the following
> 
>         int i = convert<int>::from(str, 0)(locale_ = new_locale, throw_ = 
> true);
> 
> (a list inside single quotes). I remember Andrey mentioning I could do 
> that with a Boost.Parameter macro but I admit of not being bright enough 
> to figure it out by myself. Any help would be greatly appreciated.
> 
> Thanks,
> Vladimir.
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