Re: [Boost-Users] Re: Why scoped_ptr dost provide custom deallocation?

bjorn.karlsson@readsoft.com wrote:

HANDLE hPrinter=0; OpenPrinter(_T("Some printer"),&hPrinter,0); if (boost::shared_ptr<void> p(hPrinter,&ClosePrinter)) {

}

While this works, it doesn't convey the intent of the code (nor preserve it): the resource should typically not be shared, only scoped, and I believe that scoped_ptr would be a perfect fit.

A zero-overhead scoped_ptr would require a helper class here: struct printer_deleter { void operator()(void * pv) const { ClosePrinter(pv); } } scoped_ptr p(hPrinter); The other option is scoped_ptr p(hPrinter, &ClosePrinter); that would increase sizeof(scoped_ptr) and is of questionable utility. :-) There is always the option to define a dedicated printer class, of course.