I am coming up against a vexing conundrum in my code base. I can't quite tell why my code generates this error, but (for example) std::string does not. class String { public: String(const char*str); friend String operator+ ( const String& lval, const char *rval ); friend String operator+ ( const char *lval, const String& rv...
Hello, I need to extract the RSA public key from a RSA private key using OpenSSL. I'm currently using RSAPublicKey_dup() passing the RSA* private key to get the public key. However, while the call seems to work, I cannot load (or use) this public key using the openssl command-line tool. If I generate the public key using the command-l...
While searching for some functions in C++ STL documentation I read that push and pop for priority queues needs constant time. http://www.cplusplus.com/reference/stl/priority_queue/push/ "Constant (in the priority_queue). Although notice that push_heap operates in logarithmic time." My question is what kind of data structure is used...
Maybe I missed something, but I cant figure out why Visual Studio 2008 isn't seeing the rdbuf() procedure. Here is my code: 16. #include "DebugBuffer/BufferedStringBuf.h" 17. 18. BufferedStringBuf debug_buffer(256); 19. std::cout.rdbuf(&debug_buffer); The BufferedStringBuf class is from this page: http://www.devmaster.net/forums/showt...
I'm convinced at this point that I should be creating subclasses of std::exception for all my exception throwing needs. Now I'm looking at how to override the what method. The situation that I'm facing, it would be really handy if the string what returns be dynamic. Some pieces of code parse an XML file for example, and adding a positio...
I have a need to create a utility in Suze Linux. The utility will make modifications to some text files, and then use the information in those text files to program a device in the computer using a different executable which accepts command line parameters. I am fluent in c#, but have never worked with Linux. Should I take the time to...
I was just reading a little bit on them from http://www.cplusplus.com/doc/tutorial/namespaces/ and it seems like a struct is capable of the same things? Or even a class for that matter. Maybe someone here can better define what a namespace is, and how it differs from a struct/class? ...
I'm trying to bring a C++ library into C#, so naturally I am trying to make a C++/CLI project. In visual studio I created a new project (Visual C++ project, class library). I then tried to make a test class out of the pre-generated "Class1" namespace Test { public ref class TestIt { public: void DoWork() {...
As far as I understand the wording in 5.2.9 Static cast, the only time the result of a void*-to-object-pointer conversion is allowed is when the void* was a result of the inverse conversion in the first place. Throughout the standard there is a bunch of references to the representation of a pointer, and the representation of a void poi...
One of the exercises in TC++PL asks: Write a function that either returns a value or that throws that value based on an argument. Measure the difference in run-time between the two ways. Great pity he never explaines how to measure such things. I'm not sure if I'm suppose to write simple "time start, time end" counter, or are the...
I want to process an image in C++. How can I access the 3D array representing the JPEG image as is done in MATLAB? ...
My objective is to take directions from a user and eventually a text file to move a robot. The catch is that I must use Cstrings(such as char word[];) rather than the std::string and tokenize them for use. the code looks like this: void Navigator::manualDrive() { char uinput[1]; char delim[] = " "; char *token; cout ...
I'm switching from C++ to C because I'm rebuilding my toy interpreter. I was used to vectors for dynamic allocation of objects like tokens or instructions of my programs, stacks and mainly strings with all their aspects. Now, in C I'm not going to have all these anymore. I know that I will have to use a lot of memory management, too. ...
#include <iostream> #include <fstream> using namespace std; int main () { ofstream testfile; testfile.open ("test.txt"); testfile << "success!\n"; testfile.close(); return 0; } 1)called "g++ testfile.cpp" 2)created "test.txt" 3)called "chmod u+x a.out" 4)??? 5)file remains blank. I feel like an idiot for failing at somethin...
What is the default values for members of a struct and members of a class in c++, and how do these rules differ (e.g. between classes/structs/primitives/etc) ? Are there circumstances where the rules about the default values differs ? ...
hello I have template that looks like this: 100 template<size_t A0, size_t A1, size_t A2, size_t A3> 101 struct mask { 103 template<size_t B0, size_t B1, size_t B2, size_t B3> 104 struct compare { 105 static const bool value = (A0 == B0 && A1 == B1 && A2 == B2 && A3 == B3); 106 }; 107 }; ... 120 const typename boost...
Hi, im starting a new project and for the first time i want to be cross-platform. But the tricky is my project would involve listen server, cryptos etc., etc. So i was wondering what is the best solution for cross-platform development (OpenSSL, instead of MSCrypto etc.) that would be easy to write with VS2010 (yeah the RC). The language ...
I will be starting a project which requires communication between distributed nodes(the project is in C++). I need a lightweight message passing library to pass very simple messages(basically just strings of text) between nodes. The library must have the following characteristics: No external setup required. I need to be able to get ev...
I'd like to know how to check out the speed of a file being uploaded in real time using the curl library in C++. This is what I have written: curl_easy_getinfo(curl,CURLINFO_SPEED_UPLOAD,&c); But the manual says that it shows average speed, but even this doesn't seem to work with me, because I can only see a 0. There is one more thin...
Is there any way to retrieve information about how many extra displays there are besides the main one, how they are numbered, what the dimensions are, etc? I know this is pretty easy in .net land. ...