Re: [boost] [function] function wrapping with no exception safetyguarantee

Subject: Re: [boost] [function] function wrapping with no exception safetyguarantee
From: Emil Dotchevski (emil_at_[hidden])
Date: 2010-10-07 22:37:36

On Thu, Oct 7, 2010 at 6:22 PM, Peter Dimov <pdimov_at_[hidden]> wrote:
> Daniel Walker wrote:
>
>> void do_stuff(boost::function<int(int)> f)
>> {
>>   // ...
>>   if(f) {
>>       // Remove the exception safety guarantee for this block.
>>       boost::unsafe_function<int(int)> g = f;
>>       for(int i = 0; i < INT_MAX; ++i)
>>           g(i);
>>   }
>>   // ...
>> }
>
> This example implies that unsafe_function is inherently more efficient, but
> this need not be so. An empty function may point to throw_bad_function_call
> instead of NULL.

Right, and what the empty boost::function does needs not be decided at
compile time, it can be done in the constructor.

Emil Dotchevski
Reverge Studios, Inc.
http://www.revergestudios.com/reblog/index.php?n=ReCode