changes seems to be done but not applied

[Akillioon]

I'm trying to take multiple lines of string to a vector, like "hello you", "hello world".
and then through for_each changes the ASCII value on all characters in the string including blank. to be the next ASCII.

It's here I seem to fail ( or I think).

 string operator()(string s)
  {
    for ( char &c : s )
      {
	cout<<c<<" "<<"changes till: ";
	c = {c+1};
	
		cout<<c<<endl;
	++sum_changes;
      }

    return s;
  }

--------

#include <fstream>
#include <algorithm>
#include <iostream>
#include <iterator>
#include <vector>
#include <cctype>
using namespace std;

template<typename T>
ostream& operator<<(ostream& os, const vector<T>& v)
{
  copy(v.cbegin(), v.cend(), ostream_iterator<T>(os, "\n"));
  return os;
}

class scrambler
{
public:
  scrambler (int init=0) :  sum_changes(init), c2(init) {}

  string operator()(string s)
  {
    for ( char &c : s )
      {
	cout<<c<<" "<<"changes till: ";
	c = {c+1};
	//c = toupper( c );
		cout<<c<<endl;
	++sum_changes;
      }

    return s;
  }

  int get_change()const{return sum_changes;}
private:
  double sum_changes;
  char c2;
  string s2;
};



int main()
{
  vector<string> v;
  string in;
  
  while(getline(cin,in,'\n'))
    {
      v.push_back(in);
    }
  scrambler scramble;
  for_each(v.begin(),v.end(),ref(scramble));




  cout <<"String outputs after changes:\n " << v << endl;
  cout<<"total changes done: "<<scramble.get_change()<<endl;
  return 0;
}

Example run:

~/Desktop $ ./a.out
abc
a changes till: b
b changes till: c
c changes till: d
String outputs after changes:
abc

total changes done: 3

[vlad from moscow]

Maybe you meant

string operator()(string &s)

?

[Akillioon]

The change made it work. but i'm a bit confused because I thought the
Return s; would do the thing.

[vlad from moscow]

You do not use the return value.

[Akillioon]

I just realized it now, Thanks to you :)