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

Subject: Re: [boost] Unicode: what kind of binary compatibility do we want?
From: Mathias Gaunard (mathias.gaunard_at_[hidden])
Date: 2009-06-02 12:21:55

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.

> It might be useful to determine compatibility when the library starts, perhaps via an initialization call, and use the Strategy Pattern to determine the implementation.  (When compatible, a property's accesses are unchecked.  When incompatible, the property's accesses are checked.)

That would mean virtual function call overhead, which should be higher 
than a simple branching in an inlined function.