Can I compare with R_PosInf

Question

Is it reliable to compare with R_PosInf so that for any double number

number < R_PosInf == true

Answer 1

Easy enough to try!

Code

#include <Rcpp.h>

// [[Rcpp::export]]
bool compToInf(double x) {
  return x < R_PosInf;
}

/*** R
compToInf(.Machine$double.xmax)   ## largest representable double
compToInf(Inf)
*/

Demo

R> sourceCpp("/tmp/so50229770.cpp")

R> compToInf(.Machine$double.xmax)   ## largest representable double
[1] TRUE

R> compToInf(Inf)
[1] FALSE
R>