Re: [Boost-users] tribool question

From: Richard Hadsell (hadsell_at_[hidden])
Date: 2005-07-01 09:31:35

Serge Skorokhodov wrote:

>So there is no reason to prevent customization? Because an uninitialized
>value should be unknown from the domain point of view (at least in the
>domain I'm currently work in:)
>
IIRC, there was a discussion of this during the development of tribool.  
Both the name and the purpose of the third state vary according to 
application.  It could mean "not determined yet," or "we have found that 
it can never be determined," or possibly some others, depending on your 
understanding of the language.  Your application must want the "not 
determined yet" meaning, which makes sense for the default value.  Other 
meanings could choose any of the 3 states as the default value.

If it makes sense for the rest of tribool's behavior, perhaps there is a 
way to make the default constructor value configurable, just as the name 
of the third state is configurable.  At least, someone might like to add 
a rationale discussion in the docs, in order to lay the issue to rest.

-- 
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