are scope guards (scope(exit, success, failure)) zero-cost abstractions?

[Daniel Kozak]

Yes, it add, but is almost zero

On Thu, Feb 8, 2018 at 12:00 PM, Timothee Cour via Digitalmars-d-learn <
digitalmars-d-learn at puremagic.com> wrote:

> I know that, my question is whether it adds any runtime overhead over
> naive way (which is to call the "bar" finalizer before each return
> statement)  in the case where no exception is thrown
>
>
> On Thu, Feb 8, 2018 at 2:44 AM, Mike Parker via Digitalmars-d-learn
> <digitalmars-d-learn at puremagic.com> wrote:
> > On Thursday, 8 February 2018 at 10:09:12 UTC, Timothee Cour wrote:
> >>
> >> I'm curious whether scope guards add any cost over the naive way, eg:
> >>
> >> ```
> >> void fun(){
> >>   ...
> >>   scope(success) {bar;}
> >>   ...
> >> }
> >> ```
> >>
> >> vs:
> >>
> >> ```
> >> void fun(){
> >>   ...
> >>   if(foo1){
> >>     bar;  // add this before each return
> >>     return;
> >>   }
> >>   ...
> >>   bar;
> >>   return;
> >> }
> >> ```
> >>
> >> For scope(success) and scope(failure), the naive way would anyway
> >> involve try/catch statements but what about scope(exit)? Does the
> >> zero-cost exception model (zero cost being for non-thrown exceptions)
> >> guarantee us that scope(success) has 0 overhead over naive way?
> >
> >
> > Scope guards are lowered to the equivalent try/catch/finally blocks
> anyway.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.puremagic.com/pipermail/digitalmars-d-learn/attachments/20180208/9809ed86/attachment.html>