On 5/27/11 10:08 AM, Stewart, Robert wrote:
Krzysztof Czainski wrote:
That's for base class chaining to avoid multiple inheritance, just like the operators library has it.
struct X : boolable<X, addable<X> > {...}; It's also for cases in which one would normally have this:
struct derived : base { ... };
Then, to provide safe-bool functionality for derived, one would do the following to avoid MI:
struct derived : safe_bool<derived, base> { ... };
Okay, I think I see now. It looks to me that most of the time it really wouldn't be a big deal at all to just add boolable<> (and addable<> etc.) as another base class via. multiple inheritance, but I can see how the additional flexibility is useful for times when you want to avoid multiple inheritance in order to have the clear chain of command offered by single inheritance. Thank you for the explanations! Cheers, Greg