iostream

unsigned char *teta = ....; ... printf("data at %p\n", teta); // prints 0xXXXXXXXX How can I print variable address using iostream s? Is there a std:: ??? feature like std::hex to do this kind of conversion (address -> string), so std::cout << std::??? << teta << std::endl will print that address? (no sprintf's, please ;)) Cast to void* : unsigned char* teta = ....; std::cout << "data at " << static_cast<void*>(teta) << "\n"; iostreams generally assume you have a string with any char* pointer, but a void* pointer is just that - an address (simplified), so the iostreams can't do anything other

I'm trying to hold the screen on my output using the header file <iostream.h> , but I don't know any equivalent function to the getch() & clrscr() functions of <conio.h> in <iostream.h> or any other C++ library. Are there any such functions? if you work on windows you can use system("pause"), this will give you "press any key to continue" message. Stephen Veiss The conio.h functions are compiler extensions to the language, not part of C or C++. There isn't a direct replacement in standard C++. For getch(), int ch = std::cin.get(); is probably the closest equivalent -- but bear in mind that

C++11 introduces char16_t and char32_t to facilitate working with UTF-16- and UTF-32-encoded text strings. But the <iostream> library still only supports the implementation-defined wchar_t for multi-byte I/O. Why has support for char16_t and char32_t not been added to the <iostream> library to complement the wchar_t support? In the proposal Minimal Unicode support for the standard library (revision 2) it is indicated that there was only support among the Library Working Group for supporting the new character types in strings and codecvt facets. Apparently the majority was opposed to supporing

I would like to read and write pi as 3,141592 instead of 3.141592 , as using the comma is common in many European countries. How can I accomplish this with iostream s? In other words cout << 3.141592; should print 3,141592 to standard output. You should use basic_ios::imbue to set the preferred locale. Take a look here: http://www.cplusplus.com/reference/ios/ios_base/imbue/ Locales allow you to use the preferred way by the user, so if a computer in Italy uses comma to separate decimal digits, in the US the dot is still used. Using locales is a Good Practice. But if you want to explicitly force

Is there anyway to read a known number of bytes, directly into an std::string, without creating a temporary buffer to do so? eg currently I can do it by boost::uint16_t len; is.read((char*)&len, 2); char *tmpStr = new char[len]; is.read(tmpStr, len); std::string str(tmpStr, len); delete[] tmpStr; std::string has a resize function you could use, or a constructor that'll do the same: boost::uint16_t len; is.read((char*)&len, 2); std::string str(len, '\0'); is.read(&str[0], len); This is untested, and I don't know if strings are mandated to have contiguous storage. You could use a combination of

I would like to load the contents of a text file into a vector<char> (or into any char input iterator, if that is possible). Currently my code looks like this: std::vector<char> vec; std::ifstream file("test.txt"); assert(file.is_open()); while (!(file.eof() || file.fail())) { char buffer[100]; file.read(buffer, 100); vec.insert(vec.end(), buffer, buffer + file.gcount()); } I do not like the manual use of a buffer (Why 100 chars? Why not 200, or 25 or whatever?), or the large number of lines that this took. The code just seems very ugly and non-C++. Is there a more direct way of doing this? If

A few weeks back I was using std::ifstream to read in some files and it was failing immediately on open because the file was larger than 4GB. At the time I couldnt find a decent answer as to why it was limited to 32 bit files sizes, so I wrote my own using native OS API. So, my question then: Is there a way to handle files greater than 4GB in size using std::ifstream/std::ostream (IE: standard c++) EDIT: Using the STL implementation from the VC 9 compiler (Visual Studio 2008). EDIT2: Surely there has to be standard way to support file sizes larger than 4GB. Apparently it depends on how off_t

How can I print 0x0a, instead of 0xa using cout? #include <iostream> using std::cout; using std::endl; using std::hex; int main() { cout << hex << showbase << 10 << endl; } This works for me in GCC: #include <iostream> #include <iomanip> using namespace std; int main() { cout << "0x" << setfill('0') << setw(2) << hex << 10 << endl; } If you are getting sick and tired of iostream's formatting quirkiness, give Boost.Format a try. It allows good-old-fashioned, printf-style format specifiers, yet it is type-safe. #include <iostream> #include <boost/format.hpp> int main() { std::cout << boost: