Re: [boost] [function] "paranoia" vs efficiency

Subject: Re: [boost] [function] "paranoia" vs efficiency
From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2009-10-02 12:08:32

Domagoj Saric wrote:
> As far as I can see boost::function<>::operator() performs:
> if (this->empty())
>       boost::throw_exception(bad_function_call());
> before invoking the stored function (object)...
> My question is why or why only this "checked"/"safe" approach/method of
> invocation exists?

I think this branching can be effectively elided without sacrificing 
safety if boost::function maintains never-empty internal guarantee. IOW, 
if function::empty() returns true, then the function object is actually 
pointing to some private function that simply throws upon being invoked.