You can use conio.h under windows. You would simply read and process any keyboard input in a while loop. Here is a simple example:
#include <conio.h>
#include <iostream>
#include <list>
int main()
{
    std::list<char> myChars; // to store what your chars
    std::cout << "START WRITING: ";
    while(true)
    {
        // read the character and perform some logic
        char val = _getch();
        if (static_cast<int>(val) == 8) // backspace: pop_back
        {
            myChars.pop_back();
            std::cout << "\b" << " " << "\b";
            /* no idea how to go up to the previous line in a console :( */
        }
        else if (static_cast<int>(val) == 13) // enter/return: new line
        {
            myChars.push_back('\n');
            std::cout << "\n";
        }
        else if (static_cast<int>(val) == 27) // escape: exit
        {
            break;
        }
        else // push_back
        {
            myChars.push_back(val);
            std::cout << val;
        }
    }