Message-ID: <BANLkTikp58hYW3WQQ4e7c4Xbbctg8vEh3g@mail.gmail.com>
Date: 2011-05-14T16:14:57Z
From: Jelmer Ypma
Subject: [Rcpp-devel] Exposing constructors with same number of arguments with different types using Rcpp Modules
In-Reply-To: <19918.40359.229999.700861@max.nulle.part>
Excellent, thanks for the update.
Jelmer
On Sat, May 14, 2011 at 17:20, Dirk Eddelbuettel <edd at debian.org> wrote:
>
> On 13 May 2011 at 11:58, Dirk Eddelbuettel wrote:
> | On 13 May 2011 at 16:35, Jelmer Ypma wrote:
> | | Dear Rcpp-list,
> | |
> | | I'm trying to expose multiple constructors of a C++ class to R using
> | | modules. Here is an example of what I want to do based on the Uniform
> | | example
>
> [...]
>
> | | Compilation works fine (on Windows using RTools, Rcpp_0.9.4.1,
> | | inline_0.3.8), but the R code cannot distinguish between two
> | | constructors with the same number of arguments, but with different
> | | types for the arguments and always calls Uniform(double, double). The
> |
> | If I recall correctly, we have determined that this cannot work. It is one of
> | these 'obvious in hindsight' issue. ?Recall that R does the dispatch, and R
> | cannot differentiate between ?foo(double) and ?foo(int) ?as it is not typed.
> |
> | So I think you will have to differentiate the constructors by name. Sorry
> | about that, but even Rcpp modules has its limits.
> |
> | And I may of course be wrong too in which case Romain may come in and
> | clarify.
>
> I got a brief word in with Romain who clarified that this ought to be
> possible but may not be right now. ?So stay tuned -- with some luck Romain
> may be able to improve on what we currently have.
>
> In the meantime you may have to make do with different setter functions.
>
> Dirk
>
> --
> Gauss once played himself in a zero-sum game and won $50.
> ? ? ? ? ? ? ? ? ? ? ?-- #11 at http://www.gaussfacts.com
>