#include <algorithm>#include <iostream>#include <string>#include <type_traits>#include <vector> struct S{int value{0};bool specified_state{true};     S(int v=0): value{v}{}    S(Sconst& rhs)=default;    S(S&& rhs){*this= std::move(rhs);}    S& operator=(Sconst& rhs)=default;    S& operator=(S&& rhs){if(this!=&rhs){            value= rhs.value;            specified_state= rhs.specified_state;            rhs.specified_state=false;}return*this;}}; template<typename T>std::ostream& operator<<(std::ostream& os,std::vector<T>const& v){for(constauto& s: v){ifconstexpr(std::is_same_v<T, S>)            s.specified_state? os<< s.value<<' ': os<<". ";elseifconstexpr(std::is_same_v<T,std::string>)            os<<(s.empty()?".": s)<<' ';else            os<< s<<' ';}return os;} int main(){std::cout<<std::left; std::vector<S> a{1,2,3,4,5,6,7};std::vector<int> b{1,2,3,4,5,6,7};std::vector<std::string> c{"α","β","γ","δ","ε","ζ","η"}; std::cout<<"vector<S>\tvector<int>\tvector<string>\n";std::cout<< a<<"  "<< b<<"  "<< c<<'\n';     std::ranges::shift_left(a,3);    std::ranges::shift_left(b,3);    std::ranges::shift_left(c,3);std::cout<< a<<"  "<< b<<"  "<< c<<'\n';     std::ranges::shift_right(a,2);    std::ranges::shift_right(b,2);    std::ranges::shift_right(c,2);std::cout<< a<<"  "<< b<<"  "<< c<<'\n';     std::ranges::shift_left(a,8);// has no effect: n >= last - first    std::ranges::shift_left(b,8);// ditto    std::ranges::shift_left(c,8);// dittostd::cout<< a<<"  "<< b<<"  "<< c<<'\n'; //  std::ranges::shift_left(a, -3); // UB}

vector<S>       vector<int>     vector<string>1 2 3 4 5 6 7   1 2 3 4 5 6 7   α β γ δ ε ζ η4 5 6 7 . . .   4 5 6 7 5 6 7   δ ε ζ η . . .. . 4 5 6 7 .   4 5 4 5 6 7 5   . . δ ε ζ η .. . 4 5 6 7 .   4 5 4 5 6 7 5   . . δ ε ζ η .