Re: [boost] [scope_guard] New revision available+ namingconsideration

From: Andrey Semashev (andysem_at_[hidden])
Date: 2005-09-21 13:28:49

Rob Stewart wrote:
>>>> - The naming of arm/disarm methods of scope guard. They are used to
>>>> change the activity status of the guard. Personally, I feel fine
>>>> with them but the commonly used name for disabling the guard is
>>>> "dismiss" and I just can't figure out its suitable counterpart in
>>>> English. I wonder if anyone have a proposal about this.
>>>
>>> "Dismiss" would be the right word in English to tell the guard to
>>> go away and do nothing more.
>>
>> Yes but what about its antipod - a function to enable the guard?
>> Note that the guard may even be initially disabled (that's another
>> reason I didn't like dismiss) and then it may be enabled in some
>> place.
>
> I see.  I thought you somehow knew of "dismiss" in another
> language and didn't know the English word for it.
>
> I think Markus is right: summon is the opposite of dismiss for a
> guard.  The question is whether it reads well when used:
>
>    guard g;
>    if (something) g.dismiss();
>    ...
>    if (whatever) g.summon();
>

Well, as for me the "summon" name doesn't look very good. It looks like 
something should come from the "other side" :). The Brian's proposal 
("guard") looks better but intersects with the class name itself. Maybe some 
other versions?

>>>> - The naming of the function make_guarded_call (in previous version
>>>> it was make_transaction) is what I'm not sure of. This function in
>>>> addition to a scope_guard creation calls some another functor. The
>>>> semantic is grouping the "do" and "undo" actions in the user code.
>>>> Does anyone have a better name?
>>>
>>> How about "call_guarded" or "invoke_guarded?"
>>
>> That might do. But doesn't the common make_ prefix mean that
>> something (a guard in this case) should be created?
>
> I took your question to mean that you were naming a function
> template that created a guard, called a function (object), and
> then destroyed the guard.  Now it sounds as though you're
> creating a function object that does that and you want to name
> the function template that creates the function object.  In that
> case, "make_guarded_caller" sounds about right.

I'm sorry if I made myself not clear enough. The function is supposed to do 
the following:
- Take two function objects
- Execute the first one immediately
- Create a guard object that will call the second functor on destruction
- Return the guard (user may bind it to a reference, which is typedefed to 
boost::scope_guard)

So from the user's point of view the function executes the "do" action and 
returns a guard to perform "undo" action. This looks like some kind of 
transaction - the action shall be rolled back unless everything is ok and 
the result is committed (read: the guard is disarmed).
The word "transaction" though is what I'd like to avoid. It is too wide 
spread an has to do with databases which is not the case.