unseekable stream test

unseekable_stream_test.cpp

//https://wandbox.org/permlink/WDyGG2FRC7FNuoXy

#include <iostream>

int main()
{
    // unseekable stream test
    std::ostream &os = std::cout;
    printf("initial state: %d\n", std::cout.fail());
    os << "hello world" << std::endl;
    printf("after output: %d\n", std::cout.fail());
    os.tellp();
    printf("after tellp: %d\n", std::cout.fail());
    os.seekp(10, std::ios::beg);
    printf("after seekp: %d\n", std::cout.fail());
}