http://stackoverflow.com/questions/43182003/concatenate-stringvector-with-rcpp/43182453#43182453

push_back.cpp

#include <Rcpp.h>
using namespace Rcpp;

// [[Rcpp::export]]
IntegerVector rcpp_build(int n)
{
    IntegerVector res;
    for (int i = 0; i < n; i++) {
        res.push_back(i);
    }
    return res;
}

// [[Rcpp::export]]
IntegerVector stl_build(int n)
{
    std::vector<int> res;
    for (int i = 0; i < n; i++) {
        res.push_back(i);
    }
    return wrap(res);
}

/*** R

microbenchmark::microbenchmark(
    "Rcpp" = rcpp_build(1e4),
    "STL" = stl_build(1e4),
    times = 200L
)
# Unit: microseconds
#  expr       min        lq        mean    median        uq        max neval cld
#  Rcpp 74293.567 76430.353 89823.14842 77650.885 79364.228 209266.312   200   b
#   STL    30.789    37.631    70.79363    65.379    71.271   1672.862   200   a

*/