将char*转换为SEXP

Question

我需要将const char*已知长度转换为a Rcpp::RawVector以返回到R.

Rcpp::wrap适用于多种类型,但似乎不起作用char *.

Answer 1

library(Rcpp)
library(inline)

ƒ <- rcpp(body='
const char* text = "this is some text";
Rcpp::RawVector rv(strlen(text));
for(unsigned int i=0; i<strlen(text); i++) { rv[i] = text[i]; }
return(rv);
')

ƒ()
##  [1] 74 68 69 73 20 69 73 20 73 6f 6d 65 20 74 65 78 74

rawToChar(ƒ())
## [1] "this is some text"

UPDATE

@nrussell的方法是更好的方式:

#include <Rcpp.h>
#include <cstring>

// [[Rcpp::export]]
Rcpp::RawVector to_raw(const char* str) {
    Rcpp::RawVector res(str, str + std::strlen(str));
    return res;
}