用this_thread :: sleep_for进行侦听？

Question

I'm testing using this_thread::sleep_for() to create an object that acts similarly to cout , except when printing strings it will have a small delay between each character. However, instead of waiting 0.1 seconds between each character, it waits about a second then prints it all at once. Here's my code:

#include <iostream>
#include <chrono>
#include <thread>

class OutputObject
{
    int speed;
public:
    template<typename T>
    void operator<<(T out)
    {
        std::cout << out;
    }
    void operator<<(const char *out)
    {
        int i = 0;
        while(out[i])
        {
            std::this_thread::sleep_for(std::chrono::milliseconds(speed));
            std::cout << out[i];
            ++i;
        }
    }
    void operator=(int s)
    {
        speed = s;
    }
};

int main(int argc, char **argv)
{
    OutputObject out;
    out = 100;
    out << "Hello, World!\n";
    std::cin.get();
    return 0;
}

Any idea what I'm doing wrong?

Edit: CoryKramer pointed out that std::flush is required for it to act in real time. By changing std::cout << out[i]; to std::cout << out[i] << std::flush; , I solved my problem!

Answer 1

Streams have buffer, so cout won't print text before you flush stream, for example endl flushes stream and adds '\\n' also call to cin automatically flushes buffered data in stream. Try to use this:

while(out[i])
{
   std::this_thread::sleep_for(std::chrono::milliseconds(speed));
   std::cout << out[i];
   std::cout.flush();
   ++i;
}