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Subject: Re: [boost] [safebool] Can we generalize it and put it into utilities?
From: Stewart, Robert (Robert.Stewart_at_[hidden])
Date: 2009-04-01 08:39:12

On Tuesday, March 31, 2009 5:06 PM
Ilya Sokolov wrote:
> Vladimir.Batov wrote:
> > Repeating safe-bool scaffolding over and over again is a
> > real nuisance. It is worse for the end users as not exactly
> > everyone is intimately familiar with the issue and the
> > safe-bool workaround. Can we generalize it and put
> > something like the following into utilities?
> Given a large number of known problems [1] and the
> forthcoming addition of explicit conversion operators to c++,
> it might be better to provide a macro.
> [1]

There are definitely portability workarounds necessary for shared_ptr, based upon Peter's work in that library. If any of those actually apply to safe_bool, they can be captured in the safe_bool class Vladimir has implemented. Of course, some of the older compilers can be ignored by this new utility.

To account for the need for operator bool() in the SunPro case, a macro would certainly be needed. However, such an operator is hardly a safe bool, so that case might simply be ignored. If support for that is included, I suggest that the macro be introduced as a means to extend support to older compilers so that those not needing such support can forego the macro.

Rob Stewart robert.stewart_at_[hidden]
Software Engineer, Core Software using std::disclaimer;
Susquehanna International Group, LLP

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