[Rcpp-devel] Segfaults

[Darren Cook]

>>> ...The job of the thin R wrapper function is to sanity check
>>> and/or coerce the vars to the correct type before they are past
>>> to the inline'd function to avoid the segfault.
>> 
>> Why do you do this in R, instead of in the C++ function? (The 
>> advantage of doing it in the C++ function is that there is no way 
>> to accidentally skip the validation.)
> 
> Simply because it's less tedious to write in R, so I guess I'm a bit
>  lazy that way.
> 
> I'm a bit more aggressive with my naming though, ie. if I want the 
> function to be called `func`, the R function `func` is the function 
> that does the initial type checking/coersion which then calls down to
> the inlined Rcpp function, which would would be something like 
> `.func.cpp`, which is named thusly so that I make sure I never 
> "forget" that I shouldn't be calling that directly ... 

Thanks for the reply Steve. Perhaps ".func.no.validation" makes it
really hard to forget in 6 months time :-)

Another advantage of validation in a wrapper (whether that wrapper is
done in R or C++) is you can deliberately skip over it when you know
your parameters are valid (e.g. because the parent function has already
checked them). A common technique for optimization.

Darren


-- 
Darren Cook, Software Researcher/Developer

http://dcook.org/work/ (About me and my work)
http://dcook.org/blogs.html (My blogs and articles)