c++11 - Best way to store and construct member const array or strings -

suppose have class this:

class foo {   const arr;   foo(b arg): arr(arg) { } }; 

what efficient choice types of a , b. thinking this,

class foo {   const std::initializer_list<std::string> arr;   foo(std::initializer_list<std::string> arg): arr(arg) { } }; 

but think copy-construct strings in arr. i'd able this:

std::string str1("there"), str2("now"); foo bar({"hello",str1,std::move(str2)}); 

and have rvalue strings in brackets moved arr.

should use std::initializer_list, or std::vector, or else?

define arr std::vector<std::string>, , ctor's argument std::initializer_list<std::string>, have guessed.