Le 18/04/2018 à 13:32, Dirk Eddelbuettel a écrit :
On 18 April 2018 at 10:26, Georgi Boshnakov wrote: | I may be missing something here but | it doesn't seem right to introduce silent coercion of NULL to vectors, etc., | especially if it would become imposed on everybody using Rcpp/Armadillo. | Even the "convenience" of this is questionable. Agreed. I am also not yet convinced by Serguei's argument. It seems a little invasive for an unclear (to me) use case.
I can describe my own case which made me search for a such solution. I have an Rcpp/Armadillo function accepting in an optional argument a vector of uvec type. It can be called from R and I can call it from other C++ functions of the same package too. Nullable<IntegerVector> mechanism was cumbersome but sufficient (note that there is no possible Nullable<uvec>) when only R calls were planned. But when it comes to calls from C++ I'll have to juggle with wrap() too. Both of Nullable<T> (as well as special code for dealing with NULL case) and wrap() become unnecessary with a neat declaration f(..., uvec v, ...). So that an R call with 'c()' can pass as well as C++ calls with an empty uvec without any additional hassle for treating NULL case. Serguei. _______________________________________________ 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