Re: [boost] Unicode: what kind of binary compatibility do we want?

Subject: Re: [boost] Unicode: what kind of binary compatibility do we want?
From: Ilya Sokolov (ilyasokol_at_[hidden])
Date: 2009-06-03 02:43:50

Rogier van Dalen wrote:
> On Tue, Jun 2, 2009 at 17:21, Mathias Gaunard
> <mathias.gaunard_at_[hidden]> wrote:
>> Stewart, Robert wrote:
>>
>>> I don't know the implications of this, but I generally dislike the idea of
>>> a silent fallback.  I'd prefer to see two interfaces: one throws an
>>> exception on out of range values and one that accepts a default value to
>>> return in those cases.
>> If the character has some new property value it means it had the default
>> property value (which isn't really a property, it's more like a "other" or
>> "any") in the previous versions, I'm fairly sure Unicode guarantees this.
> 
> I think that's correct. The Unicode Standard 5.0 says (section 3.5, D26, p 84):
> 
> "Default property value: The value (or in some cases small set of
> values) of a property
> associated with unassigned code points or with encoded characters for which the
> property is irrelevant."

By this definition you can't return the default for assigned code point 
for with the property is not irrelevant.