istream

At 50:40 of http://channel9.msdn.com/Events/GoingNative/2013/Writing-Quick-Code-in-Cpp-Quickly Andrei Alexandrescu makes a joke about how not efficient/slow istream is. I had an issue in the past with ostream being slow and fwrite being significantly faster (reducing many seconds when running the main loop once) but I never understood why nor looked into it. What makes istream and ostream slow in C++? or at least slow compared to other things (like fread/fget, fwrite) which would equally satisfied the needs. Dietmar Kühl Actually, IOStreams don't have to be slow! It is a matter of implementing

#include <iostream> #include <string> using namespace std; int main() { string username; cout<< "username" ; cin >> username; } So I was curious on what's the difference between these two codes, I heard it's the same thing but if it is then why two ways of doing it then? #include <iostream> #include <string> using namespace std; int main() { string username; cout << "username" ; getline (cin,username) ; } The difference is that std::getline — as the name suggests — reads a line from the given input stream (which could be, well, std::cin ) and operator>> reads a word 1 . That is, std::getline

What is the difference between istreambuf_iterator and istream_iterator ? And in general what is the difference between streams and streambufs? I really can't find any clear explanation for this so decided to ask here. IOstreams use streambufs to as their source / target of input / output. Effectively, the streambuf-family does all the work regarding IO and the IOstream-family is only used for formatting and to-string / from-string transformation. Now, istream_iterator takes a template argument that says what the unformatted string-sequence from the streambuf should be formatted as, like

I have a char* and the data length that I'm receiving from a library, and I need to pass the data to a function that takes an istream. I know I can create a stringstream but that will copy all the data. And also, the data will surely have 0s since it's a zip file, and creating a stringstream will take the data until the first 0 I think. Is there any way to create an istream from a char* and it's size without copying all the data? Here's a non-deprecated method found on the web , has you derive your own std::streambuf class, but easy and seems to work: #include <iostream> #include <istream>