hi. the Rcpp-modules document, section 2.2.2, mentions that one can
write a routine to disambiguate between different constructors taking
the same number of arguments.
i wonder, in the case one has *not* provided such a disambiguator, would
it be possible to offer up an error message, maybe at compile time?
(and point the programmer at the relevant document.)
attached is a test case which compiles, but gets a runtime error it
took me a bit of head scratching, compiling Rcpp with debug symbols so i
could follow the action, etc.
(in *this* case, the specific error message is: "Error: not an S4
object".)
cheers, Greg
----
// the question here is: how to return an R list of reference objects
// to run, first put the source in inc
// (inc <- <SINGLEQUOTE><SOURCE><SINGLEQUOTE>)
// then do something like:
#if 0
require(inline);
require(Rcpp);
setClass("box", representation(
ne="integer"));
setMethod(
"initialize",
signature("box"),
definition=function(.Object, ne) {
.Object@ne <- ne;
return(.Object);
});
cld <- cxxfunction(,plugin="Rcpp", includes=inc);
clm <- Module("test5_module", getDynLib(cld));
space2d <- clm$space2d;
new(space2d, new("box", 1L)) # this will work
new(space2d, matrix(0, nrow=4, ncol=4)) # this will fail
#endif /* 0 */
#include <R.h>
#include <RcppCommon.h>
#include <Rcpp/S4.h>
class box {
public:
int ne;
public:
box() {}
box(const int _ne) {
ne = _ne;
}
box(const box& _box) {
ne = _box.ne;
}
};
#if defined(RcppCommon_h)
namespace Rcpp {
template <> inline SEXP wrap(const box& box) {
S4 ret("box");
ret.slot("ne") = wrap(box.ne);
return wrap(ret);
}
template <> inline box as(SEXP sexp) {
box box;
S4 s4(sexp);
box.ne = s4.slot("ne");
return box;
}
}
#endif /* defined(RcppCommon_h) */
#include <Rcpp.h>
class space2d {
public:
box global; // the box in global coordinates
public:
space2d(box bbox, int initval = 0) {
global = bbox;
}
space2d(Rcpp::IntegerMatrix matrix) {
int
minx = 0,
maxx = matrix.ncol()-1,
miny = 0,
maxy = matrix.nrow()-1;
global = box(minx*miny*maxx*maxy);
}
};
RCPP_EXPOSED_CLASS(space2d)
using namespace Rcpp;
RCPP_MODULE(test5_module) {
class_<space2d>("space2d")
.constructor<box,int>()
.constructor<box>()
.constructor<Rcpp::IntegerMatrix>();
}
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