I want to write to a std::stringstream without any transformation of, say line endings. I have the following code: void decrypt(std::istream& input, std::ostream& output) { while (input.good()) { char c = input.get() c ^= mask; output.put(c); if (output.bad()) { throw std::ru...
within Qt is it possible to use cin?? I can use cout but cannot find anywhere where it shows how to use ciin within a Qt Console application many thanks, gda2004 ...
I using readLine() method for reading the text, but i am not aware of how many text can read that method. Ex. String str = in.readLine(); how many texts can read and store on "str"? ...
I have a problem with with my output when I write to I file I get squares when I put endl to change lines. std::ofstream outfile (a_szFilename, std::ofstream::binary); outfile<<"["<<TEST<<"]"<<std::endl; I get something like this in my file plus the other outputs don't write on the next line but on the same one. [TEST]square appa...
I need to prevent my double to print in scientific notation in my file, when I do this outfile<<X; ...
I'm writing a lambda calculus interpreter for fun and practice. I got iostreams to properly tokenize identifiers by adding a ctype facet which defines punctuation as whitespace: struct token_ctype : ctype<char> { mask t[ table_size ]; token_ctype() : ctype<char>( t ) { for ( size_t tx = 0; tx < table_size; ++ tx ) { t[tx] = isal...
I've seen people do things like.... istringstream ibuf; if (ibuf >> zork >> iA >> Comma >> iB) now I guess the value depends on what >>iB exposes but exactly what is that and what does it mean? Does true mean all the ietms were extracted? Also, after an expression like ibuf >> zork >> iA >> Comma >> iB; is there any way to ...
Why does the following not work: #include <iostream> #include <fstream> #include <stack> std::stack<std::ifstream> s; -PT ...
Is it possible to interoperate with a C++ iostream and python? I'm using boost-python and want to wrap a function that has istream and ostream as arguments. ...
I'm trying to update a random-access binary file using the std::iostream interface with separate get/put positions managed via seekg/seekp. Everything works fine with stringstream, but when I create a file descriptor-based stream using Boost.Iostream (specifically boost::iostreams::stream<boost::iostreams::file_descriptor>), the get/put ...
I have a 2884765579 bytes file. This is double checked with this function, that returns that number: size_t GetSize() { const size_t current_position = mFile.tellg(); mFile.seekg(0, std::ios::end); const size_t ret = mFile.tellg(); mFile.seekg(current_position); return ret; } I then do: mFile.se...
Can anybody explain the difference between cerr cout and clog and why does different objects are proposed? I know the differences are as below: 1) cout can redirected but cerr can't 2) clog can use buffer. I am confused about the point 2, I am grateful if anybody can elaborate it more. ...
In the answer to this question ovanes states: Please be aware that boost::lexical_cast is much slower as atoi. I also use it very often in a performance non-critical code. The problem with lexical_cast is that it uses stringstream for conversion. If you are working in a multi-threaded environement any stream class from ...
Hi In such code, what it is called, \\n like this? cout<<"Hello\\n \'world\'!"; What's the basic rule about such characters? ...
I have an application that wants to read word by word, delimited by whitespace, from a file. I am using code along these lines: std::istream in; string word; while (in.good()) { in>>word; // Processing, etc. ... } My issue is that the processing on the words themselves is actually rather light. The major time consumer is...
I got some problems with EOF and stdio in a communication pipeline between a python process and a C++ program. I have no idea what I am doing wrong. When I see an EOF in my program I clear the stdin and next round I try to read in a new line. The problem is: for some reason the getline function immediatly (from the second run always, the...
Hi, I'm trying to figure out how to redirect istream to wxwidgets. I was able to accomplish redirecting ostream, here's how (so you know what I mean): wxTextCtrl* stdoutctrl = new wxTextCtrl(...); wxStreamToTextRedirector redirect(stdoutctrl); //Redirect ostream std::cout<<"stdout -- does this work?"<<std::endl; //It worked. I'...
#include <iostream> #include <fstream> using namespace std; int main () { ofstream myfile; myfile.open ("test.txt"); return 0; } fstream is derived from iostream, why should we include both in the code above? I removed fstream, however, there is an error with ofstream. My question is ofstream is derived from ostream, why fstrea...
I want to read both formatted text and binary data from the same iostream. How can I do that? Why? Imagine this situation: You have different resources, and resource loaders for them, that take a std::istream as a parameter. And there are a "resource source" that provides these streams. Resources can be both text and binary and I need t...
This might be a repeat, but my google-fu failed to find it. I want to print numbers to a file using the stl with the number of decimal places, rather than overall precision. So, if I do this: int precision = 16; std::vector<double> thePoint(3); thePoint[0] = 86.3671436; thePoint[0] = -334.8866574; thePoint[0] = 24.2814; ofstream file...