On 23 July 2013 at 11:50, Steve Jaffe wrote: | on: Tue, 23 Jul 2013 11:37:25 -0500 | Dirk Eddelbuettel <e...@debian.org> wrote: | | > | A singleton does make things easier. However, I still want to know how to | > | expose C structure with provided `free`-like function because sometimes we | > | cannot use singleton. | > | > Manage your objects carefully, and don't call free() on NULL pointers. | | According to the C standard, it is safe to call free on a null pointer. Similarly, according to the C++ standard, it is safe to call 'delete' on a null pointer. | | Thus there is no need ever to test a pointer for null before free-ing/delete-ing. | | However, it *is* good practice to assign null to a pointer *after* free-ing/delete-ing, since that ensures that any subsequent calls to free/delete will be safe. | | What is dangerous is calling free/delete twice on the same *non-null* pointer.
Thanks for the correction. I obviously shouldn't have mixed malloc/free with new/delete in the discussion. I rarely need to write code that uses new/delete these days as I much prefer to rely on STL containers -- a programming style advocated by just about every modern C++ text (incl Stroustrup, 2013, 4th ed). And by just about all Rcpp examples we provide. Dirk -- Dirk Eddelbuettel | e...@debian.org | http://dirk.eddelbuettel.com _______________________________________________ Rcpp-devel mailing list Rcpp-devel@lists.r-forge.r-project.org https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
