[Rcpp-devel] Possible error in setequal ??

[Søren Højsgaard]

Dear all,

There might be an error in setequal() from sugar. Consider this

#include <Rcpp.h>
using namespace Rcpp;

//[[Rcpp::export]]
bool seteq1(CharacterVector x, CharacterVector y){
  return setequal(x,y);
}

//[[Rcpp::export]]
bool seteq2(CharacterVector x, CharacterVector y){
  return
	(((CharacterVector) setdiff(x,y)).length()==0) &
	(((CharacterVector) setdiff(y,x)).length()==0) ;
}

The examples below does not give what I expect when calling seteq1 whereas seteq2 gives what I expect. Am I completely wrong here?

Regards
Søren

seteq1(c(1,2,3), c(3,2,1))
seteq1(c("a","b"), c("a","b"))
seteq1(c(1,2,3), c(3,2))
seteq1(c("a","b"), c("a","b","k"))

seteq2(c(1,2,3), c(3,2,1))
seteq2(c("a","b"), c("a","b"))
seteq2(c(1,2,3), c(3,2))
seteq2(c("a","b"), c("a","b","k"))

> seteq1(c(1,2,3), c(3,2,1))
[1] FALSE

> seteq1(c("a","b"), c("a","b"))
[1] FALSE

> seteq1(c(1,2,3), c(3,2))
[1] FALSE

> seteq1(c("a","b"), c("a","b","k"))
[1] FALSE

> seteq2(c(1,2,3), c(3,2,1))
[1] TRUE

> seteq2(c("a","b"), c("a","b"))
[1] TRUE

> seteq2(c(1,2,3), c(3,2))
[1] FALSE

> seteq2(c("a","b"), c("a","b","k"))
[1] FALSE