Re: [boost] Safe bool idiom

From: Douglas Gregor (gregod_at_[hidden])
Date: 2003-09-11 10:20:40

On Thursday 11 September 2003 09:36 am, Daniel Frey wrote:
> This new idiom should be as safe as the current one, but it uses a real
> operator bool() for bool conversion, so no overhead can slip in. To be
> fair, it also has one drawback: The error message a user receives when
> converting a shared_ptr to int, float, ... is not as nice as today.

My only remaining concern with the new idiom is that it breaks is_convertible. 
With the member function pointer version, 
is_convertible<something_bool_testable, int>::value == false; with the 
private conversion to an integral type, this results in a compiler error. 

I don't know what to do about this, or if it will break much user code, but it 
will break some code.

        Doug