I'm reading data from a stream into a char array of a given length, and I'd like to make the maximum width of read to be large enough to fit in that char array. The reason I use a char array is that part of my specification is that the length of any individual token cannot exceed a certain value, so I'm saving myself some constructor c...
I have a an object I'd like to be able to read and write to/from a QDataStream. The header is as follows: class Compound { public: Compound(QString, QPixmap*, Ui::MainWindow*); void saveCurrentInfo(); void restoreSavedInfo(QGraphicsScene*); void setImage(QPixmap*); QString getName(); private: QString name, hom...
I'm trying to use fread/ifstream to read the first 2 bytes of a .csv with BOM info. But following code always skips the first two bytes (which are 'FF FE'): ifstream is; is.open (fn, ios::binary ); char buf[2]; is.read(buf, 2); is.close(); using FILE*/fread does no better. ...
Hi I was trying to output unicode string to a console with iostreams and failed. I found this: Using unicode font in c++ console app and this snippet works. SetConsoleOutputCP(CP_UTF8); wchar_t s[] = L"èéøÞǽлљΣæča"; int bufferSize = WideCharToMultiByte(CP_UTF8, 0, s, -1, NULL, 0, NULL, NULL); char* m = new char[bufferSize]; WideChar...
If you try to cout a pointer to a volatile type, even a volatile char pointer where you would normally expect cout to print the string, you will instead simply get '1' (assuming the pointer is not null I think). I assume output stream operator<< is template specialized for volatile pointers, but my question is, why? What use case motivat...
I have a function void write<typename T>(const T&) which is implemented in terms of writing the T object to an ostream, and a matching function T read<typename T>() that reads a T from an istream. I am basically using iostreams as a plain text serialisation format, which obviously works fine for most built-in types, although I'm not sure...
Is it possible to tie a C++ output stream to another output stream? I'm asking because I've written an ISAPI extension in C++ and I've written ostreams around the WriteClient and ServerSupportFunction/HSE_REQ_SEND_RESPONSE_HEADER_EX functions - one ostream for the HTTP headers and one for the body of the HTTP response. I'd like to tie t...
I've implemented an ostream for debug output which sends ends up sending the debug info to OutputDebugString. A typical use of it looks like this (where debug is an ostream object): debug << "some error\n"; For release builds, what's the least painful and most performant way to not output these debug statements? ...
I would like to be able to write: cout << enumalpha << Monday; and get printed on console: Monday P.S. Monday is an enum type. ...
Hiya. I'm trying to read a file line by line to a string type variable using the following code: #include <iostream> #include <fstream> ifstream file(file_name); if (!file) { cout << "unable to open file"; exit(1); } string line; while (!file.eof()) { file.getline(line,256); cout<<line; } file.close(); it won't co...
I have a class that contains decoded video frames. I would like my decoder to use an output_iterator to write those frames to different targets. In order to support writing directly to a file, I want to overload operator << for my decoded frame class (for use with ostream_iterator). The problem is, that operator << is meant to be used fo...
I am working on a C++ based command line tool and I want to capture the user's keystrokes in real-time without requiring them to hit Return to commit the input. I can't seem to find an iostream call to support this kind of behavior but I recall from my college years that it can be done. Can anyone point me in the right direction? ...
I have a random piece of code, I use for reading from CSV files... and it's fine... until after about 2000 reads... then the getline line fails with an access violation to 0xcccccc... which I assume means that the input stream (file) has been cleared... Not that I know why :) int CCSVManager::ReadCSVLine ( fstream * fsInputFile, ...
The problem is that I want to output Mathematica compatible floating point numbers. The only difference with the standard IOStream or printf output format is that the exponential e is replaced by *^: Standard C/C++ output format: 1.23e-4 Mathematica format: 1.23*^-4 Is there a way to manipulate streams to achieve this effect? My origi...
#include<iostream> #include<fstream> #include<cstdlib> #include<iomanip> using namespace std; int main() { ifstream in_stream; // reads itemlist.txt ofstream out_stream1; // writes in items.txt ifstream in_stream2; // reads pricelist.txt ofstream out_stream3;// writes in plist.txt ifstream in_stream4;// read recipt.tx...
could someone also tell me if the actions i am attempting to do which are stated in the comments are correct or not. i am new at c++ and i think its correct but i have doubts #include<iostream> #include<fstream> #include<cstdlib> #include<iomanip> using namespace std; int main() { ifstream in_stream; // reads itemlist.txt ofstream out...
I have a project that requires me to insert a filter into a stream so that outgoing data will be modified according to the filter. After some research, it seems that what I want to do is create a filtered_streambuf like this: template <class StreamBuf> class filtered_streambuf: public StreamBuf { ... } And then insert a filtered_strea...
I have a class that is derived from ostream: class my_ostream: public std::ostream { // ... } I want to make a manipulator (for example do_something), that works specifically to this class, like this: my_ostream s; s << "some text" << do_something << "some more text"; I did the following: std::ostream &do_something(std::ostrea...
Is there a better way to serialize an ObjC object than using /NSKeyedArchive? I need to distribute the object through a C++ std:ostream-like object to put on another computer. The object has over 122 members of various types... for which wants me to [coder encodeObject: (id) forKey: @"blah"]; for all of them... Does anyone have a...
I'd like to write a simple ostream which wraps an argument ostream and changes the stream in some way before passing it on to the argument stream. The transformation is something simple like changing a letter or erasing a word What would a simple class inheriting from ostream look like? What methods should I override? ...