Hi, In src/attrib.c, the comment for the function R_data_class is:
``` /* the S4-style class: for dispatch required to be a single string; for the new class() function; if(!singleString) , keeps S3-style multiple classes. Called from the methods package, so exposed. */ SEXP R_data_class(SEXP obj, Rboolean singleString) ``` I am obviously writing this because I'd wish to see it in the API, and I think that the above (a package shipped with R does need this as part of the API) is a pretty good case for having it. Best, Laurent PS: I have found a similar request made some time in the past (one of the points in https://stat.ethz.ch/pipermail/r-devel/2007-October/047070.html ). ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
