Re: [Boost-users] [mpl]... is there an mpl::string

Subject: Re: [Boost-users] [mpl]... is there an mpl::string
From: Ovanes Markarian (om_boost_at_[hidden])
Date: 2009-04-08 15:42:21

On Wed, Apr 8, 2009 at 7:51 PM, Eric Niebler <eric_at_[hidden]>wrote:

> Ovanes Markarian wrote:
>
>> Eric Niebler wrote:
>>
>>> You mean, how did I discover the nature of the implementation-defined
>>> behavior for each compiler? It wasn't by reading any docs. I just played
>>> around with various compilers until
>>> I found what worked. I found some compiler bugs in the process,
>>> too. See:
>>>
>>>
>>> https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=334208
>>>
>>
>> Interesting. Ok, but if a string maps to an integer it means that I
>> can only pass 4 characters at once on a 32bit platform???
>>
>
> Strings don't map to integers. Multicharacter literals do. And yes, that
> means in general that you can only reliably count on being able to
> encode a 4 char sequence in a multicharacter literal.
>
Yes, sure. It is already late in Munich and I have headache. I meant exactly
that.

>
>
>  I just looked over your tests and did not get immediately that these
>> all use char test sequences.
>>
>
> I don't follow you.

Sorry again. I mean that your tests are based on 4-char literals, which I
did not pay attention.

>
>  I used a slightly different approach in my previous use case.
>>
>> template<char const* Str> string {...};
>>
>> extern const char some_string[] ={"abcd efg..."};
>>
>> typedef string<some_string>          my_string_type;
>>
>
> Sure, but that gets hard to use, and you can't use this to compute new
> strings at compile time.

:) But for my special use case that was enough. I defenitely share your
opinion, that a library implementation should be more flexible, than my
special use case impl was. On the other hand I too oft see programmers which
are ignorant and even don't give a chance to a great approach. I can imagine
their reaction when seeing:

typdef mpl::string<'some', 'cool', 'type'>    compile_time_string;

>
>
>  Would be cool to find a solution of really passing strings like:
>>
>> typedef string<"abcd efg..">     some_other_type;
>>
>
> And if wishes were fishes we'd all cast nets. ;-)

Would be nice to get there ;)

Cheers,
Ovanes