Hi, ----- Original Message ----- From: <Vladimir.Batov@wrsa.com.au> To: <boost@lists.boost.org> Cc: <Vladimir.Batov@wrsa.com.au> Sent: Sunday, March 29, 2009 11:18 PM Subject: [boost] [safebool] Can we generalize it and put it into utilities?
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?
struct safebool { typedef void (safebool::*unspecified_bool_type)() const; typedef unspecified_bool_type result;
explicit safebool(bool v) : value_(v) {}
operator result() const { return value_ ? &safebool::internal_bool : 0; }
private:
void internal_bool() const {};
bool value_; };
That way all we (and the users) will have to do to deploy the technique will be
class Foo { ... operator safebool::result() const { return safebool(my_condition); } };
This seems simple and hassle-free.
Yes, this seems much more simple and open than the mixin approach. Why do you use result instead of unspecified_bool_type. The following it enough clear to me class Foo { ... operator safebool::unspecified_bool_type() const { return safebool(my_condition); } }; I like it anyway, Vicente