diff --git a/R/parse.R b/R/parse.R
index dd9e9ff..bc37054 100644
--- a/R/parse.R
+++ b/R/parse.R
@@ -7,7 +7,6 @@
 #' @export
 ada_url_parse <- function(url, decode = TRUE) {
     url <- utf8::as_utf8(url)
-    ##len <- vapply(url, function(x) nchar(x, type = "bytes"), integer(1), USE.NAMES = FALSE)
     url_parsed <- Rcpp_ada_parse(url)
     if (isTRUE(decode)) {
         return(.decoder(url_parsed))
diff --git a/src/RcppExports.cpp b/src/RcppExports.cpp
index 3deeda4..f5a35f5 100644
--- a/src/RcppExports.cpp
+++ b/src/RcppExports.cpp
@@ -11,12 +11,12 @@ Rcpp::Rostream<false>& Rcpp::Rcerr = Rcpp::Rcpp_cerr_get();
 #endif
 
 // Rcpp_ada_parse
-DataFrame Rcpp_ada_parse(CharacterVector input_vec);
+DataFrame Rcpp_ada_parse(const CharacterVector& input_vec);
 RcppExport SEXP _adaR_Rcpp_ada_parse(SEXP input_vecSEXP) {
 BEGIN_RCPP
     Rcpp::RObject rcpp_result_gen;
     Rcpp::RNGScope rcpp_rngScope_gen;
-    Rcpp::traits::input_parameter< CharacterVector >::type input_vec(input_vecSEXP);
+    Rcpp::traits::input_parameter< const CharacterVector& >::type input_vec(input_vecSEXP);
     rcpp_result_gen = Rcpp::wrap(Rcpp_ada_parse(input_vec));
     return rcpp_result_gen;
 END_RCPP
diff --git a/src/adaR.cpp b/src/adaR.cpp
index 8861abb..95f024c 100644
--- a/src/adaR.cpp
+++ b/src/adaR.cpp
@@ -1,6 +1,6 @@
 #include "adaR.h"
 
-std::string charsub(ada_string stringi) {
+std::string charsub(const ada_string stringi) {
   const char* res = stringi.data;
   size_t len = stringi.length;
   ada_owned_string stringi_new = ada_idna_to_unicode(res, len);
@@ -10,7 +10,7 @@ std::string charsub(ada_string stringi) {
 }
 
 // [[Rcpp::export]]
-DataFrame Rcpp_ada_parse(CharacterVector input_vec) {
+DataFrame Rcpp_ada_parse(const CharacterVector& input_vec) {
   unsigned int n = input_vec.length();
   CharacterVector href(n);
   CharacterVector protocol(n);
@@ -22,7 +22,7 @@ DataFrame Rcpp_ada_parse(CharacterVector input_vec) {
   CharacterVector pathname(n);
   CharacterVector search(n);
   CharacterVector hash(n);
-  for (int i = 0; i < n; i++) {
+  for (unsigned int i = 0; i < n; i++) {
     String s = input_vec[i];
     const char* input = s.get_cstring();
     ada_url url = ada_parse(input, std::strlen(input));