Re: [boost] data_binding library for boost... Any interest?

From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2008-07-24 21:39:22

AMDG

Brian Davis wrote:
> I am only
> providing a simple example for discussion and hopefull inclusion of data
> binding concept in boost and ....ultimately modify the C++ compiler to
> provide for a lighter weight solution (events based on modifications of
> integral types) - Ouch ... yes I know what I am asking here... see the last
> part of the example output for why I ask this.
>   

What exactly do you mean by a lighter weight solution?
Allowing events to be registered for an arbitrary int would
have the following consequences:

The compiler would have to insert extra code for every
integer assignment, severely degrading performance regardless of
whether this feature is used--except where the compiler can
prove that no event is registered for a particular integer.

The function
    f(int& i) {
        i = 0;
    }
could throw.  This would break a lot of exception safety guarantees.

Every assignment could modify any variable, effectively forbidding
many compiler optimizations based on pointer alias analysis.

In Christ,
Steven Watanabe