CODEWITHSUNDEEP
c++c++11
Ivaylo Valchev
Ivaylo Valchev

Reputation: 10425

How to check if i/ostream is empty?

I'm trying to write a simple function that will pause my console.

Simple enough, but I want it to work in both cases: when the stream is empty, you just use std::cin.get(); or std::getchar();; and when the stream is not empty, if you have inputted anything during the course of the program, you would have to use std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n'); std::cin.get();;

So, I wanna write a function which would handle both with a simple if statement, if possible. Unfortunately I'm insanely bad with C++ streams. I hope someone with more knowledge in the area can help or point out the obvious function I've missed. Thanks!

#include <iostream>
#include <limits>

void pause()
{
    if (std::cin.eof()) //I don't know what I'm doing here. Don't judge, lol
    {
        std::cin.get();
    }
    else
    {
        std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
        std::cin.get();
    }
}

int main()
{
    int i = 0;
    std::cin >> i;          //if I comment this line, I would have to press enter twice
    std::cout << "Hello world!";                         //to close the console
    pause();
}

Upvotes: 0

Views: 3956

Answers (1)

Ivaylo Valchev
Ivaylo Valchev

Reputation: 10425

void pause()
{
    if (std::cin.rdbuf()->in_avail() > 0)
        std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
    std::cin.get();
}

Upvotes: 1

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